2017-2019 Audi A4/S4 — KB & S4 Style Rear Diffuser
Upgrade the rear of your 2017-2019 Audi A4 / S4 with your choice of two rear diffuser styles. Both are crafted from high-quality ABS plastic and designed for a clean, bolt-on fit using factory mounting points.
Style Options:
- KB Style — Aggressive multi-fin diffuser available in Black (primer-ready) or Carbon Fiber (hydrographic hydrodip). Fits both S-line/S4 and Non S-line trim levels.
- S4 Style w/ Exhaust Tips — OEM+ diffuser with integrated dual exhaust tip surrounds for a factory S4 look. Available for S-line and S4 trim levels only.
Key Features:
- Material: High-quality ABS plastic — primer-ready, paint to match or custom finish
- Designed for 2017-2019 Audi A4 / S4 using factory mounting points; may require fitment and trimming adjustments based on vehicle trim options — professional installation recommended
- Bolt-on installation — no cutting of the factory bumper required for standard fitment
- Fits A4 and S4 models only — not compatible with RS4
Fitment: 2017-2019 Audi A4 / S4 — B9. KB Style fits both S-line/S4 and Non S-line. S4 Style w/ Exhaust Tips fits S-line and S4 only (requires factory S-line rear bumper configuration).
The Carbon Fiber finish is a premium hydrographic carbon fiber hydrodip, pre-applied over ABS — no painting required.
Production & Lead Time: These rear diffusers are custom-manufactured to order. Please allow 1–2 weeks for production before your order ships. Orders cannot be modified or cancelled once production has begun.
Original: $301.99
-65%$301.99
$105.70More Images
2017-2019 Audi A4/S4 — KB & S4 Style Rear Diffuser
Upgrade the rear of your 2017-2019 Audi A4 / S4 with your choice of two rear diffuser styles. Both are crafted from high-quality ABS plastic and designed for a clean, bolt-on fit using factory mounting points.
Style Options:
- KB Style — Aggressive multi-fin diffuser available in Black (primer-ready) or Carbon Fiber (hydrographic hydrodip). Fits both S-line/S4 and Non S-line trim levels.
- S4 Style w/ Exhaust Tips — OEM+ diffuser with integrated dual exhaust tip surrounds for a factory S4 look. Available for S-line and S4 trim levels only.
Key Features:
- Material: High-quality ABS plastic — primer-ready, paint to match or custom finish
- Designed for 2017-2019 Audi A4 / S4 using factory mounting points; may require fitment and trimming adjustments based on vehicle trim options — professional installation recommended
- Bolt-on installation — no cutting of the factory bumper required for standard fitment
- Fits A4 and S4 models only — not compatible with RS4
Fitment: 2017-2019 Audi A4 / S4 — B9. KB Style fits both S-line/S4 and Non S-line. S4 Style w/ Exhaust Tips fits S-line and S4 only (requires factory S-line rear bumper configuration).
The Carbon Fiber finish is a premium hydrographic carbon fiber hydrodip, pre-applied over ABS — no painting required.
Production & Lead Time: These rear diffusers are custom-manufactured to order. Please allow 1–2 weeks for production before your order ships. Orders cannot be modified or cancelled once production has begun.
Product Information
Product Information
Shipping & Returns
Shipping & Returns
Description
Upgrade the rear of your 2017-2019 Audi A4 / S4 with your choice of two rear diffuser styles. Both are crafted from high-quality ABS plastic and designed for a clean, bolt-on fit using factory mounting points.
Style Options:
- KB Style — Aggressive multi-fin diffuser available in Black (primer-ready) or Carbon Fiber (hydrographic hydrodip). Fits both S-line/S4 and Non S-line trim levels.
- S4 Style w/ Exhaust Tips — OEM+ diffuser with integrated dual exhaust tip surrounds for a factory S4 look. Available for S-line and S4 trim levels only.
Key Features:
- Material: High-quality ABS plastic — primer-ready, paint to match or custom finish
- Designed for 2017-2019 Audi A4 / S4 using factory mounting points; may require fitment and trimming adjustments based on vehicle trim options — professional installation recommended
- Bolt-on installation — no cutting of the factory bumper required for standard fitment
- Fits A4 and S4 models only — not compatible with RS4
Fitment: 2017-2019 Audi A4 / S4 — B9. KB Style fits both S-line/S4 and Non S-line. S4 Style w/ Exhaust Tips fits S-line and S4 only (requires factory S-line rear bumper configuration).
The Carbon Fiber finish is a premium hydrographic carbon fiber hydrodip, pre-applied over ABS — no painting required.
Production & Lead Time: These rear diffusers are custom-manufactured to order. Please allow 1–2 weeks for production before your order ships. Orders cannot be modified or cancelled once production has begun.
