2014-2020 BMW M3 F80 & M4 F82 SM Style Carbon Fiber Rear Diffuser and Lip

Enhance the rear profile of your BMW M3 or M4 with this SM Style carbon fiber rear diffuser and lip kit. Designed for the F80 and F82 chassis, this rear aero upgrade creates a more aggressive lower bumper appearance while complementing the vehicle’s factory body lines.

The SM Style design adds greater visual definition across the lower rear bumper area and gives the vehicle a more dynamic, motorsport-inspired presence. Its rear diffuser, rear lip, and side cap combination enhances aerodynamic styling and pairs naturally with compatible front lips, side skirts, trunk spoilers, and other exterior upgrades.

Crafted from carbon fiber, this rear diffuser and lip kit provides a premium exterior accent with a performance-focused appearance. Designed for compatible 2014-2020 BMW M3 F80 and M4 F82 models, each package includes one rear lip, one rear diffuser, and one pair of side caps.

Product Specifications

Key Features

• SM Style rear diffuser and lip kit designed for compatible BMW M3 and M4 models
• Compatible with listed F80 and F82 chassis applications
• Creates a more aggressive lower rear bumper profile
• Adds greater visual definition across the rear diffuser and rear lip areas
• Includes side caps for a more complete rear-end styling upgrade
• Carbon fiber construction with a premium exterior appearance
• Designed to complement compatible front lips, side skirts, and trunk spoilers
• Suitable for sedan and coupe exterior builds
• Includes one rear lip, one rear diffuser, and one pair of side caps
• Provides a coordinated rear bumper styling upgrade

Package Includes

• One rear lip
• One rear diffuser
• One pair of side caps

Note: Brackets, clips, screws, double-sided tape, automotive adhesive, and additional mounting hardware may not be included unless otherwise specified.

Installation

• Designed for installation along the compatible lower factory rear bumper
• Professional installation is recommended for accurate alignment and secure mounting
• Test fit the rear lip, diffuser, and side caps before drilling, trimming, applying adhesive, or completing final installation
• Clean and degrease all mounting surfaces thoroughly before installation
• Use suitable automotive screws, clips, brackets, or adhesive as required
• Additional mounting hardware or supporting brackets may be necessary
• Minor drilling, trimming, sanding, or alignment adjustment may be required
• Confirm adequate clearance around the exhaust outlets and surrounding bumper components
• Verify secure attachment and sufficient ground clearance before driving

Fitment

• 2014-2020 BMW M3 Sedan F80
• 2014-2020 BMW M4 Coupe F82

United States: Free shipping available to the lower 48 states across all items. Other states will incur a shipping charge.

Worldwide: Free shipping is available for Complete Headlights, Taillights, DRLs. For custom headlight retrofits, carbon fiber products, and performance products, there will be a shipping charge.  

Please note:
• For Retrofits, you are purchasing a headlight modification service.
• If you select "Shipping own headlights to BayOptiks for modification", you are required to send us your headlights.
• If you choose "Purchase new OEM headlights", we will order and modify a new OEM headlight for you.
• Once your customizations are complete, we will ship it to you!

• Complete Headlights: 3-5 business days for order processing plus shipping time.
• Custom & Pre-Built Headlights: 6-8 weeks depending on the complexity and component availability.
• New OEM and cores: 6-8 weeks plus an additional 4-8 weeks as these are special orders base on the vehicle VIN due to different versions (North American, European, etc.)
• DRLs, Taillights, Brake Pads, and Carbon Fiber Aero: 3-5 business days for order processing, plus shipping time.
• Lens Replacements: 1-3 weeks plus shipping time.

Please note, we do not have control over the time frames of our vendors, manufacturers, and delivery services as they may delay processes in regards to components and shipment.