2017-2019 For Audi A4 S4 B9 Diffuser With Large Dual Tailpipe

Product Description

Overview

Transform the rear profile of your 2017–2019 Audi A4 B9 S‑Line or S4 with this S4 style rear diffuser complete with large dual tailpipe exhaust tips. Designed specifically for the pre‑facelift B9 platform (2017–2019), this full replacement kit replaces the factory rear valance with the aggressive, sporty look of the S4 — featuring a gloss black UV‑stabilized ABS polymer construction, aggressive honeycomb design, and impressively large dual‑outlet exhaust tips that make a bold statement.

The B9 generation brought sharp, modern styling to the A4/S4 lineup. This S4‑inspired rear diffuser builds on that foundation, giving your A4 S‑Line a more commanding presence from every angle while improving rear‑end aerodynamics. The diffuser is crafted of a UV‑stabilized ABS polymer to achieve its deep high‑gloss shine and provides an aggressive and sporty style that's sure to set your vehicle apart from the rest. The oversized dual outlets are designed to fit large‑diameter aftermarket exhaust tips up to 4.5 inches, dramatically enhancing the visual impact of your rear end.

Critical Fitment Note: This diffuser is exclusively for Audi A4 B9 S‑Line (2017–2019) and S4 models. It will NOT fit Non‑S‑Line (standard) A4 bumpers or facelift B9.5 (2020–2024) models. The rear bumpers are different between S‑Line and standard, as well as between pre‑facelift and facelift, making diffuser compatibility non‑interchangeable without verification. You must have the factory S‑Line exterior package for this to fit.

Complete Conversion Kit: Includes rear diffuser, large dual exhaust tips, self‑tapping screws, 3M VHB tape, and installation manual.

Aerodynamic Benefits: The sculpted honeycomb design helps smooth airflow, reduce turbulence, and enhance rear‑end stability at higher speeds.

Serving both individual enthusiasts (B2C) and businesses (B2B):
✅ US warehouse for fast shipping
✅ CE certified for quality assurance
✅ 1‑year warranty for peace of mind
✅ Factory direct – competitive pricing
✅ Dropshipping & wholesale programs available
✅ Custom OEM/ODM orders welcome

5 Key Features

1. Aggressive S4 Style Design with Large Dual Outlets
Give your A4 B9 S‑Line or S4 the sharp, sporty look of the S4. The aggressive dual‑outlet design and sculpted lines create a bold, OEM+ appearance that dramatically enhances the rear profile. The generously sized openings accept large‑diameter exhaust tips up to 4.5 inches, making your aftermarket or stock exhaust look significantly more aggressive and performance‑oriented.

2. Complete Kit with Large Dual Tailpipe Exhaust Tips
All‑in‑one conversion kit includes the rear diffuser and large dual exhaust tips — everything you need for a full S4 style rear transformation. Features an oversized dual‑outlet design (left + right) that fits factory and most aftermarket exhaust systems, with perfectly sized openings to accept large‑diameter tips. Choose between polished stainless steel or black‑chrome finishes in extra‑large sizing to match your personal style.

3. Premium Gloss Black UV‑Stabilized ABS Construction
Manufactured from high‑quality UV‑stabilized ABS polymer — the same material used in OEM bumpers and body parts. The deep high‑gloss black finish is UV‑protected to prevent fading, yellowing, or bubbling from harsh sunlight. No painting required — ready to install out of the box. A premium pre‑preg dry carbon fiber version is also available for those seeking ultimate weight savings and weave aesthetics.

4. Direct Fitment for B9 S‑Line (2017–2019) — No Drilling Required
Engineered for a perfect OEM+ fit onto Audi A4 B9 S‑Line and S4 rear bumpers using factory mounting locations. Designed for Sedan (Saloon) body styles. Installs with no drilling, cutting, or modification of any kind required. Simply remove your currently installed valance, line up all tabs, and lightly press the diffuser in place until the tabs click into position.
⚠️ Note: This diffuser is NOT compatible with Non‑S‑Line (standard) A4 bumpers or facelift B9.5 models. You must have the factory S‑Line exterior package to install this diffuser.

5. CE & TUV MATERIALGUTACHTEN Certified
This diffuser is CE certified, meeting European safety and quality standards for automotive aftermarket parts. It has also received TUV MATERIALGUTACHTEN certification, verifying material quality and safety for road use. The product is also EPR (France/Germany) compliant, meeting environmental responsibility regulations for packaging and waste management. The product arrives with a protective film — do not remove the protective film until you are certain the product fits, as removal will void the return policy. If you decide to paint the diffuser, primer must be used first.

Specifications