Audi S4 A4 S-line (with s-line bumper,does not fit base model) B9 2017 2018 2019 with Aftermarket Parts - Rear Diffuser Carbon Fiber from CMST Tuning
Audi S4 A4 S-line (with s-line bumper,does not fit base model) B9 2017 2048 2019 with Aftermarket Parts - Rear Diffuser Carbon Fiber from CMST Tuning
Audi S4 A4 S-line (with s-line bumper,does not fit base model) B9 2017 2048 2019 with Aftermarket Parts - Rear Diffuser Carbon Fiber from CMST Tuning
Audi S4 A4 S-line (with s-line bumper,does not fit base model) B9 2017 2048 2019 with Aftermarket Parts - Rear Diffuser Carbon Fiber from CMST Tuning
Audi S4 A4 S-line (with s-line bumper,does not fit base model) B9 2017 2048 2019 with Aftermarket Parts - Rear Diffuser Carbon Fiber from CMST Tuning
Audi S4 A4 S-line (with s-line bumper,does not fit base model) B9 2017 2048 2019 with Aftermarket Parts - Rear Diffuser Carbon Fiber from CMST Tuning
Audi S4 A4 S-line (with s-line bumper,does not fit base model) B9 2017 2048 2019 with Aftermarket Parts - Rear Diffuser Carbon Fiber from CMST Tuning
Audi S4 A4 S-line (with s-line bumper,does not fit base model) B9 2017 2048 2019 with Aftermarket Parts - Rear Diffuser Carbon Fiber from CMST Tuning
CMST Tuning Carbon Fiber Rear Diffuser for Audi A4 S-Line / S4 B9 2017-2019 - Performance SpeedShop
Audi S4 A4 S-line (with s-line bumper,does not fit base model) B9 2017 2018 2019 with Aftermarket Parts - Rear Diffuser Carbon Fiber from CMST Tuning
Audi S4 A4 S-line (with s-line bumper,does not fit base model) B9 2017 2018 2019 with Aftermarket Parts - Rear Diffuser Carbon Fiber from CMST Tuning
Audi S4 A4 S-line (with s-line bumper,does not fit base model) B9 2017 2018 2019 with Aftermarket Parts - Rear Diffuser Carbon Fiber from CMST Tuning
Audi S4 A4 S-line (with s-line bumper,does not fit base model) B9 2017 2048 2019 with Aftermarket Parts - Rear Diffuser Carbon Fiber from CMST Tuning
Audi S4 A4 S-line (with s-line bumper,does not fit base model) B9 2017 2048 2019 with Aftermarket Parts - Rear Diffuser Carbon Fiber from CMST Tuning
Audi S4 A4 S-line (with s-line bumper,does not fit base model) B9 2017 2048 2019 with Aftermarket Parts - Rear Diffuser Carbon Fiber from CMST Tuning
Audi S4 A4 S-line (with s-line bumper,does not fit base model) B9 2017 2048 2019 with Aftermarket Parts - Rear Diffuser Carbon Fiber from CMST Tuning
Audi S4 A4 S-line (with s-line bumper,does not fit base model) B9 2017 2048 2019 with Aftermarket Parts - Rear Diffuser Carbon Fiber from CMST Tuning
Audi S4 A4 S-line (with s-line bumper,does not fit base model) B9 2017 2048 2019 with Aftermarket Parts - Rear Diffuser Carbon Fiber from CMST Tuning
Audi S4 A4 S-line (with s-line bumper,does not fit base model) B9 2017 2048 2019 with Aftermarket Parts - Rear Diffuser Carbon Fiber from CMST Tuning
CMST Tuning Carbon Fiber Rear Diffuser for Audi A4 S-Line / S4 B9 2017-2019 - Performance SpeedShop
Audi S4 A4 S-line (with s-line bumper,does not fit base model) B9 2017 2018 2019 with Aftermarket Parts - Rear Diffuser Carbon Fiber from CMST Tuning
Audi S4 A4 S-line (with s-line bumper,does not fit base model) B9 2017 2018 2019 with Aftermarket Parts - Rear Diffuser Carbon Fiber from CMST Tuning

CMST Tuning Rear Diffuser for Audi S4 A4 S-line B9 2017-2019 Carbon Fiber

Vendor: CMST Tuning
SKU: CMS16-078C
$980.00
$1,080.00
$980.00
Pattern/Finish: Woven 3K/Gloss
Subtotal: $980.00
Audi S4 A4 S-line (with s-line bumper,does not fit base model) B9 2017 2018 2019 with Aftermarket Parts - Rear Diffuser Carbon Fiber from CMST Tuning

CMST Tuning

CMST Tuning Rear Diffuser for Audi S4 A4 S-line B9 2017-2019 Carbon Fiber

$980.00
Audi S4 A4 S-line (with s-line bumper,does not fit base model) B9 2017 2018 2019 with Aftermarket Parts - Rear Diffuser Carbon Fiber from CMST Tuning
Audi S4 A4 S-line (with s-line bumper,does not fit base model) B9 2017 2048 2019 with Aftermarket Parts - Rear Diffuser Carbon Fiber from CMST Tuning
Audi S4 A4 S-line (with s-line bumper,does not fit base model) B9 2017 2048 2019 with Aftermarket Parts - Rear Diffuser Carbon Fiber from CMST Tuning
Audi S4 A4 S-line (with s-line bumper,does not fit base model) B9 2017 2048 2019 with Aftermarket Parts - Rear Diffuser Carbon Fiber from CMST Tuning
Audi S4 A4 S-line (with s-line bumper,does not fit base model) B9 2017 2048 2019 with Aftermarket Parts - Rear Diffuser Carbon Fiber from CMST Tuning
Audi S4 A4 S-line (with s-line bumper,does not fit base model) B9 2017 2048 2019 with Aftermarket Parts - Rear Diffuser Carbon Fiber from CMST Tuning
Audi S4 A4 S-line (with s-line bumper,does not fit base model) B9 2017 2048 2019 with Aftermarket Parts - Rear Diffuser Carbon Fiber from CMST Tuning
Audi S4 A4 S-line (with s-line bumper,does not fit base model) B9 2017 2048 2019 with Aftermarket Parts - Rear Diffuser Carbon Fiber from CMST Tuning
CMST Tuning Carbon Fiber Rear Diffuser for Audi A4 S-Line / S4 B9 2017-2019 - Performance SpeedShop
Audi S4 A4 S-line (with s-line bumper,does not fit base model) B9 2017 2018 2019 with Aftermarket Parts - Rear Diffuser Carbon Fiber from CMST Tuning
Audi S4 A4 S-line (with s-line bumper,does not fit base model) B9 2017 2018 2019 with Aftermarket Parts - Rear Diffuser Carbon Fiber from CMST Tuning

CMST Tuning

CMST Tuning Rear Diffuser for Audi S4 A4 S-line B9 2017-2019 Carbon Fiber

$980.00
Pattern/Finish: Woven 3K/Gloss
Description
Description
x

-

Upgrade Your Audi S4 A4 S-line (with s-line bumper,does not fit base model) B9 2017 2018 2019 with Aftermarket Parts - Rear Diffuser Carbon Fiber from CMST Tuning

 

 

Product Information

Vehicle Make Audi
Vehicle Model & Chassis S4 A4 S-line (with s-line bumper,does not fit base model) B9 
Vehicle Year 2017-2019
Vehicle Body Type 4 Door Sedan
Brand CMST Tuning
Product Category Rear Diffuser
Installation Method

Replacement with OEM mounting points, secure with screws or adhesive. (For best results, bumper removal recommended.) 
Professional Installation Recommendation Professional installation recommended.
Installation Guide Call in for instructions.
Package Content Rear Diffuser x 1 (1 pcs)
Material

Vacuumed Carbon:

-Real Vacuumed Carbon Fiber with UV Protection Clearcoat
Carbon Pattern Options

Woven 3k (default option):

Woven Carbon Fiber (Standard 2x2 or 3k) - the most common carbon fiber weave. 2x2 weave woven carbon fiber is the default if listing does not specify the pattern. Woven 3K carbon fiber is a lightweight and high-strength material made from bundles of 3,000 carbon filaments (referred to as "3K") that are woven into a fabric pattern, typically in a twill or plain weave. It offers excellent tensile strength, stiffness, and durability while maintaining a sleek, smooth appearance with a distinctive checkerboard pattern.

 

Forged (20% extra charge, made to order):

Forged carbon fiber - a composite material made from randomly arranged, short carbon fiber strands combined with resin and compressed in a mold. Forged carbon fiber offers greater design flexibility compared to 3K woven carbon fiber, as it can be molded into more complex shapes without compromising structural integrity. Its random fiber orientation reduces weak points caused by the directional patterns in 3K weaves, enhancing impact resistance. Additionally, it has a unique aesthetic appeal, with a marbled texture that stands out from the uniform weave of 3K carbon fiber.

 

Honeycomb Carbon (20% extra charge, made to order):

Honeycomb carbon fiber - combines woven 3K carbon fiber layers with a lightweight honeycomb weave, creating a sandwich structure that offers exceptional stiffness-to-weight ratio. This configuration provides excellent rigidity, impact resistance, and thermal insulation, making it ideal for aerospace, automotive, and high-performance sporting applications. The honeycomb weave significantly reduces material weight while maintaining strength, making it a preferred choice for lightweight structural components.



*To place order for other bespoke or creative options, please email or call in.

 
Finish Options Gloss Finish  (default option)  / Matte Finish (10% extra charge, made to order)
Estimate Installation Hours 2.5 Hours
Additional Information 


















  

 

 

About CMST Tuning



CMST Tuning uses Grade A one-piece carbon fiber sheets with a Fiberglass Reinforced Plastic (FRP) skeleton for strength and durability (except on dry carbon products, since it is not needed). Because CMST Tuning uses one-piece sheets, so you will not see any broken lines or patterns. Rather, all you will notice is just one big consistent weave pattern. In addition to this, all CMST Tuning products use a strong clear coat finish. Clear coats are shiny and durable, and they give you the nice "wet" look as opposed to a duller look from gel coats. Lastly, all of CMST Tuning's carbon sheets are built into the mold, so they do not break and split like the ones where carbon is only wrapped around the skeleton.


Important Information:


-All CMST Tuning products come with a 6-month limited clear coat warranty.
CMST Tuning Parts, unless stated otherwise, may require re-use of some factory parts for a complete installation (for example, trunk lids, hoods for some applications will require re-using the factory license plate garnish)
To avoid pre-mature aging, it is important to keep your carbon fiber product clean. Minimize exposure to the sun, and wax when necessary. This is especially important for dry carbon products, which are sold RAW and need immediate protection upon receipt.
-For hoods, for legal purpose you may need to purchase some hood pins to ensure your new hood stays closed during high-speed or aggressive driving, even if your CMST Tuning hood features built-in latches.
Professional installation is always recommended if you are unsure of your abilities (make sure they check for fitment before starting the install). In some cases, drilling may be required.
-CMST Tuning parts are either made as " Vacuumed " carbon fiber. Wet carbon fiber has a shiny finish and is smooth. or made as "Pre-preg" carbon fiber, is often more pricy but does have a better strength to weight ratio. Pre-preg carbon also has slightly better weave quality, and is less prone to very minor defects.
Carbon fiber doors are strictly for off road and track use only, due to possible safety issues.

 

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