Audi S4 Avant B9.5 BKSS Style Carbon Fiber Rear Diffuser With Exhaust Tips 2020-2025

Upgrade the rear styling and aerodynamic performance of your 2020-2025 Audi S4 Avant B9.5 with this BKSS style carbon fiber rear diffuser with exhaust tips. Designed to enhance the lower rear bumper profile, this diffuser delivers a more aggressive and performance-inspired appearance while maintaining OEM+ integration.

Engineered specifically for the B9.5 S4 Avant platform, this rear diffuser follows the factory bumper contours for precise fitment and seamless installation. The BKSS design improves rear-end definition and integrates with exhaust tip styling to create a more dynamic and sporty rear profile.

Constructed from high-quality carbon fiber materials, this diffuser offers lightweight durability, strength, and a premium finish. Available in multiple carbon fiber options, it ensures long-term reliability while enhancing both visual appeal and aerodynamic efficiency.

Product Specifications

Key Features

• Designed for 2020-2025 Audi S4 Avant B9.5 models
• BKSS style rear diffuser with integrated exhaust tip design
• Enhances rear aerodynamics and airflow management
• Improves rear bumper definition and aggressive styling
• Precision fitment aligned with factory bumper lines
• Constructed from high-quality carbon fiber materials
• Available in multiple carbon fiber finishes
• Lightweight and durable construction
• OEM+ fit and seamless integration
• Suitable for street and performance builds

Configuration Options

• CFRP – Standard carbon fiber construction with gloss finish
• FGCF – Fiberglass reinforced carbon fiber option
• Dry Carbon – Lightweight pre-preg carbon fiber with premium finish

Package Includes

• Rear diffuser

Note: Exhaust tips may vary depending on setup. Professional installation is recommended to ensure proper alignment and fitment.

Installation

• Professional installation recommended
• Mounts to factory rear bumper
• May require alignment with exhaust system
• No major modification required

Fitment

• 2020-2025 Audi S4 Avant B9.5

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.