Big Fin Carbon Fiber Rear Diffuser – BMW F80 M3 / F82 M4 | Eterna Motorworks

Big Fin Carbon Fiber Rear Diffuser – BMW F80 M3 / F82 M4 | Eterna Motorworks

Name: Big Fin Carbon Fiber Rear Diffuser – BMW F80 M3 / F82 M4 | Eterna Motorworks
Brand: Eterna Motorworks
Price: 399.00 USD
Availability: InStock

$399.00

{"id":8595851706520,"title":"Big Fin Carbon Fiber Rear Diffuser – BMW F80 M3 \/ F82 M4 | Eterna Motorworks","handle":"bmw-f80-f82-big-fin-carbon-rear-diffuser","description":"\u003cp class=\"p1\"\u003eCommand attention from every angle with the Big Fin Carbon Fiber Rear Diffuser for the F80 M3 and F82 M4. Designed for drivers who want a more aggressive rear profile, this diffuser features deep vertical fins, sharp angles, and a wide center channel for true motorsport presence. Built to match OEM bumper contours, it’s the perfect combination of aggressive styling and clean fitment.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e⸻\u003c\/p\u003e\n\u003cp class=\"p3\"\u003e\u003cb\u003eKey Features\u003c\/b\u003e\u003cb\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e• Big Fin design with deep vertical fins and wide center cutout\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e• Constructed from real carbon fiber with a 2x2 twill weave pattern\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e• Designed for flush fitment on OEM rear bumper\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e• UV-resistant gloss finish for long-term clarity and durability\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e• Matte and forged carbon options available upon request\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e⸻\u003c\/p\u003e\n\u003cp class=\"p3\"\u003e\u003cb\u003eCompatible Models\u003c\/b\u003e\u003cb\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e• BMW F80 M3 (2015–2018, Sedan)\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e• BMW F82 M4 (2015–2020, Coupe)\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e• BMW F83 M4 (2015–2020, Convertible)\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e\u003ci\u003eDesigned to fit factory rear bumper. Not compatible with aftermarket setups.\u003c\/i\u003e\u003ci\u003e\u003c\/i\u003e\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e⸻\u003c\/p\u003e\n\u003cp class=\"p3\"\u003e\u003cb\u003eWhat’s Included\u003c\/b\u003e\u003cb\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e• (1) Big Fin Carbon Fiber Rear Diffuser\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e• Tabs or mounting extensions (may vary by batch)\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e• Installation hardware not included on most products\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e⸻\u003c\/p\u003e\n\u003cp class=\"p3\"\u003e\u003cb\u003eWhy Buy From Eterna Motorworks\u003c\/b\u003e\u003cb\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"p1\"\u003eEterna Motorworks is the standard in premium aftermarket automotive parts and services. With over a decade of hands-on experience, we’ve earned the trust of enthusiasts and professional builders worldwide by delivering unmatched quality, precision fitment, and long-term credibility. Every part and service we offer is curated to meet the highest expectations in styling, performance, and reliability — both on the road and in the shop.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003eIf you’re searching for a trusted partner to set your build apart — welcome to the team.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e⸻\u003c\/p\u003e\n\u003cp class=\"p3\"\u003e\u003cb\u003eProfessional installation is highly recommended.\u003c\/b\u003e\u003cb\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"p1\"\u003eInstallation hardware not included on most products.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003eFor full fitment, installation, and store policy details, please refer to our policies before purchasing.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003eWorldwide shipping available upon request.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e⸻\u003c\/p\u003e\n\u003cp class=\"p3\"\u003e\u003cb\u003eYour next mod starts here. Upgrade your build the right way with Eterna Motorworks.\u003c\/b\u003e\u003cstrong\u003e\u003c\/strong\u003e\u003cstrong\u003e\u003c\/strong\u003e\u003c\/p\u003e","published_at":"2025-01-16T00:03:53-08:00","created_at":"2025-01-16T00:03:53-08:00","vendor":"Eterna Motorworks","type":"Carbon Fiber Rear Diffuser","tags":["f8x big fin carbon diffuser","f8x big fin diffuser","f8x carbon diffuser","f8x carbon fiber diffuser"],"price":39900,"price_min":39900,"price_max":39900,"available":true,"price_varies":false,"compare_at_price":null,"compare_at_price_min":0,"compare_at_price_max":0,"compare_at_price_varies":false,"variants":[{"id":45823867846808,"title":"Default Title","option1":"Default Title","option2":null,"option3":null,"sku":"","requires_shipping":true,"taxable":true,"featured_image":null,"available":true,"name":"Big Fin Carbon Fiber Rear Diffuser – BMW F80 M3 \/ F82 M4 | Eterna Motorworks","public_title":null,"options":["Default Title"],"price":39900,"weight":6799,"compare_at_price":null,"inventory_management":"shopify","barcode":"","requires_selling_plan":false,"selling_plan_allocations":[]}],"images":["\/\/eternamotorworks.com\/cdn\/shop\/files\/F8XBIGFINCFREARDIFFUSER_1.jpg?v=1745996193","\/\/eternamotorworks.com\/cdn\/shop\/files\/F8XBIGFINCFREARDIFFUSER_3.jpg?v=1745996193","\/\/eternamotorworks.com\/cdn\/shop\/files\/F8XBIGFINCFREARDIFFUSER_2.jpg?v=1745996193","\/\/eternamotorworks.com\/cdn\/shop\/files\/IMG_7836.jpg?v=1745996194"],"featured_image":"\/\/eternamotorworks.com\/cdn\/shop\/files\/F8XBIGFINCFREARDIFFUSER_1.jpg?v=1745996193","options":["Title"],"media":[{"alt":null,"id":40162937012376,"position":1,"preview_image":{"aspect_ratio":0.8,"height":4694,"width":3755,"src":"\/\/eternamotorworks.com\/cdn\/shop\/files\/F8XBIGFINCFREARDIFFUSER_1.jpg?v=1745996193"},"aspect_ratio":0.8,"height":4694,"media_type":"image","src":"\/\/eternamotorworks.com\/cdn\/shop\/files\/F8XBIGFINCFREARDIFFUSER_1.jpg?v=1745996193","width":3755},{"alt":null,"id":40162937045144,"position":2,"preview_image":{"aspect_ratio":0.8,"height":4694,"width":3755,"src":"\/\/eternamotorworks.com\/cdn\/shop\/files\/F8XBIGFINCFREARDIFFUSER_3.jpg?v=1745996193"},"aspect_ratio":0.8,"height":4694,"media_type":"image","src":"\/\/eternamotorworks.com\/cdn\/shop\/files\/F8XBIGFINCFREARDIFFUSER_3.jpg?v=1745996193","width":3755},{"alt":null,"id":40162937077912,"position":3,"preview_image":{"aspect_ratio":0.8,"height":4694,"width":3755,"src":"\/\/eternamotorworks.com\/cdn\/shop\/files\/F8XBIGFINCFREARDIFFUSER_2.jpg?v=1745996193"},"aspect_ratio":0.8,"height":4694,"media_type":"image","src":"\/\/eternamotorworks.com\/cdn\/shop\/files\/F8XBIGFINCFREARDIFFUSER_2.jpg?v=1745996193","width":3755},{"alt":null,"id":40162937110680,"position":4,"preview_image":{"aspect_ratio":1.25,"height":679,"width":849,"src":"\/\/eternamotorworks.com\/cdn\/shop\/files\/IMG_7836.jpg?v=1745996194"},"aspect_ratio":1.25,"height":679,"media_type":"image","src":"\/\/eternamotorworks.com\/cdn\/shop\/files\/IMG_7836.jpg?v=1745996194","width":849}],"requires_selling_plan":false,"selling_plan_groups":[],"content":"\u003cp class=\"p1\"\u003eCommand attention from every angle with the Big Fin Carbon Fiber Rear Diffuser for the F80 M3 and F82 M4. Designed for drivers who want a more aggressive rear profile, this diffuser features deep vertical fins, sharp angles, and a wide center channel for true motorsport presence. Built to match OEM bumper contours, it’s the perfect combination of aggressive styling and clean fitment.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e⸻\u003c\/p\u003e\n\u003cp class=\"p3\"\u003e\u003cb\u003eKey Features\u003c\/b\u003e\u003cb\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e• Big Fin design with deep vertical fins and wide center cutout\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e• Constructed from real carbon fiber with a 2x2 twill weave pattern\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e• Designed for flush fitment on OEM rear bumper\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e• UV-resistant gloss finish for long-term clarity and durability\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e• Matte and forged carbon options available upon request\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e⸻\u003c\/p\u003e\n\u003cp class=\"p3\"\u003e\u003cb\u003eCompatible Models\u003c\/b\u003e\u003cb\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e• BMW F80 M3 (2015–2018, Sedan)\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e• BMW F82 M4 (2015–2020, Coupe)\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e• BMW F83 M4 (2015–2020, Convertible)\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e\u003ci\u003eDesigned to fit factory rear bumper. Not compatible with aftermarket setups.\u003c\/i\u003e\u003ci\u003e\u003c\/i\u003e\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e⸻\u003c\/p\u003e\n\u003cp class=\"p3\"\u003e\u003cb\u003eWhat’s Included\u003c\/b\u003e\u003cb\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e• (1) Big Fin Carbon Fiber Rear Diffuser\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e• Tabs or mounting extensions (may vary by batch)\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e• Installation hardware not included on most products\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e⸻\u003c\/p\u003e\n\u003cp class=\"p3\"\u003e\u003cb\u003eWhy Buy From Eterna Motorworks\u003c\/b\u003e\u003cb\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"p1\"\u003eEterna Motorworks is the standard in premium aftermarket automotive parts and services. With over a decade of hands-on experience, we’ve earned the trust of enthusiasts and professional builders worldwide by delivering unmatched quality, precision fitment, and long-term credibility. Every part and service we offer is curated to meet the highest expectations in styling, performance, and reliability — both on the road and in the shop.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003eIf you’re searching for a trusted partner to set your build apart — welcome to the team.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e⸻\u003c\/p\u003e\n\u003cp class=\"p3\"\u003e\u003cb\u003eProfessional installation is highly recommended.\u003c\/b\u003e\u003cb\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"p1\"\u003eInstallation hardware not included on most products.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003eFor full fitment, installation, and store policy details, please refer to our policies before purchasing.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003eWorldwide shipping available upon request.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e⸻\u003c\/p\u003e\n\u003cp class=\"p3\"\u003e\u003cb\u003eYour next mod starts here. Upgrade your build the right way with Eterna Motorworks.\u003c\/b\u003e\u003cstrong\u003e\u003c\/strong\u003e\u003cstrong\u003e\u003c\/strong\u003e\u003c\/p\u003e"}

Request a price match

Product variants

Share:

Share

Command attention from every angle with the Big Fin Carbon Fiber Rear Diffuser for the F80 M3 and F82 M4. Designed for drivers who want a more aggressive rear profile, this diffuser features deep vertical fins, sharp angles, and a wide center channel for true motorsport presence. Built to match OEM bumper contours, it’s the perfect combination of aggressive styling and clean fitment.

⸻

Key Features

• Big Fin design with deep vertical fins and wide center cutout

• Constructed from real carbon fiber with a 2x2 twill weave pattern

• Designed for flush fitment on OEM rear bumper

• UV-resistant gloss finish for long-term clarity and durability

• Matte and forged carbon options available upon request

⸻

Compatible Models

• BMW F80 M3 (2015–2018, Sedan)

• BMW F82 M4 (2015–2020, Coupe)

• BMW F83 M4 (2015–2020, Convertible)

Designed to fit factory rear bumper. Not compatible with aftermarket setups.

⸻

What’s Included

• (1) Big Fin Carbon Fiber Rear Diffuser

• Tabs or mounting extensions (may vary by batch)

• Installation hardware not included on most products

⸻

Why Buy From Eterna Motorworks

Eterna Motorworks is the standard in premium aftermarket automotive parts and services. With over a decade of hands-on experience, we’ve earned the trust of enthusiasts and professional builders worldwide by delivering unmatched quality, precision fitment, and long-term credibility. Every part and service we offer is curated to meet the highest expectations in styling, performance, and reliability — both on the road and in the shop.

If you’re searching for a trusted partner to set your build apart — welcome to the team.

⸻

Professional installation is highly recommended.

Installation hardware not included on most products.

For full fitment, installation, and store policy details, please refer to our policies before purchasing.

Worldwide shipping available upon request.

⸻

Your next mod starts here. Upgrade your build the right way with Eterna Motorworks.

Pairs well with

Big Fin Carbon Fiber Rear Diffuser – BMW F80 M3 / F82 M4 | Eterna Motorworks

$399.00

Quick Answers

Will this fit my vehicle?

This part is made for the models listed above. If you’re unsure, send us your year, make, and model and we’ll confirm fitment for you.

What’s included?

You’ll receive exactly what’s shown. Hardware is not included unless the product description says otherwise.

How’s the install?

We recommend professional installation. If you’re local, you can book an install with us directly. Some parts may need trimming, drilling, or adjustment depending on your setup.

Do you ship internationally?

Yes, we ship worldwide. Contact us if you need help placing an international order.

Still have questions?

Reach out anytime. We’re here to help before and after your order.