Aero parts · made to order
Rear Diffusers
diffuser designs across every vehicle we tool — the second-widest category in the range, and one of the few on every marque CMST tools for.
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What the fins are for
Weave / surface
- Woven
- Forged
- Honeycomb
- 3K woven
- 1×1 weave
- Gloss
- Matte
- Paintable / unpainted
- Painted black
- Painted
Can be ordered as
- Rear diffuser only
- Rear bumper + diffuser
- Rear bumper only
- Bumper only
- Undertray only
Sections of this part are quoted separately — you do not have to take the whole assembly.
Fitment splits on
- 2.0T
- Dual Tips
- Quad Tips
- 3.2T
- 991.1 Only
- 991.2 Only
- Coupe
- Sedan
The same vehicle has more than one version — send the chassis and we will confirm which one fits.
Supply terms
- Mounts to
- Underside of the rear bumper — bumper stays on most vehicles
- Sold with
- Fins as molded; corner sections quoted separately where the vehicle has them
- Naming
- Listed as rear diffuser throughout — the older 'rear lip' wording refers to a different part in English
- MOQ
- 1 piece, mixed across parts and vehicles
- Lead time
- 7–20 days on standard orders
- Warranty
- 3 months on carbon parts from the date of fitting
- Packing
- CMST-branded export packaging with product label and parts pack
Every mold starts from the car's own body surface. A 3D-printed sample is trial-fitted on a real vehicle before the mold is cut, and the first production part is fitted again before it ships.
Find your vehicle
Every vehicle below has at least one part in this category. Open a vehicle to see its kits, the material grades it is tooled in and what each kit contains.
Marques carrying this part
Grades this part is tooled in
- Dry carbon
Prepreg, lightest, finished twill or forged weave.
- Vacuum carbon
Gloss clear coat, the volume carbon grade.
- FRP
Primed and paint-ready, for diffusers painted body color or gloss black.
- ABS
Molded-in gloss or matte black, no paint required.
Five grades run through the same molds. Ask for the grade by name on the quote — it changes weight, finish on arrival and price band, not fitment.
Questions buyers ask
- Do I need to change the rear bumper to fit a diffuser?
- On most vehicles, no — the diffuser mounts to the underside of the factory bumper. Some designs require trimming the lower bumper edge, which is stated with the part.
- Are the corner pieces included?
- It depends on the vehicle. Several kits list rear diffuser corners as a separate item because they wrap onto the bumper. Check the kit contents or ask on the quote.
- Does a diffuser work without a flat underbody?
- Less well than on a car with one, and honestly most road cars in this catalog do not have a full flat floor. The part still reduces rear lift and it is the standard visual finish for the rear of a kit.
- Why do you not call it a rear lip?
- Because in English a rear lip is a different part — the trailing edge of the boot lid. Calling the diffuser a rear lip is a translation error that causes wrong orders, so the whole catalog uses rear diffuser.
- Which grade for a diffuser?
- Carbon where it shows under the bumper. FRP where the rear of the car is being resprayed. ABS on volume orders that need no paint at all.
Related categories
Talk to the factory
Tell us the vehicle and your market
Quotes come back with kit content, material options and lead time. Tuning shops and distributors only — we do not sell to vehicle owners.
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