Triple R Composites Ford Fiesta MK8/8.5 ST/ST-Line Rear Finned Diffuser
Give your Ford Fiesta MK8/8.5 ST/ST-Line a sharper rear end with this full replacement rear finned diffuser. It adds a more aggressive, motorsport style look while helping to guide airflow under the back of the car.
- Full replacement diffuser for a clean factory-style fit
- Deep fins for a sporty, track-inspired rear view
- Gloss black gel coat finish – fit as supplied or paint if preferred
- Fibreglass construction for a strong yet lightweight part
- Designed specifically for Fiesta MK8.5 ST-Line 2021-2024 models
Why choose this diffuser
This rear finned diffuser is shaped to follow the lines of the Fiesta MK8/8.5 ST/ST-Line bumper. The bold fins give the rear of the car a wider, lower look that suits lowered and standard ride height cars. The gloss black surface works well with factory trim and contrast styling packs, and can also be painted to match your body colour if you want a more subtle finish.
The diffuser helps smooth and guide air under the rear bumper at speed. While it is mainly a visual upgrade, this cleaner airflow can give a more stable feel on the road compared with the flat, standard panel.
Fitment and installation
Designed to fit Ford Fiesta MK8/8.5 ST/ST-Line models from 2018 to 2024. It replaces the original rear diffuser section.
This product requires removal of the OEM diffuser. The new diffuser overlaps the original bumper opening. The overlap area is the polyurethane bonding zone and must be securely bonded.
A small amount of sanding along the top edge may be required to achieve the best fit where the diffuser meets the bumper. The lower edge reuses two of the OEM fixings and the supplied nuts and bolts to hold the diffuser firmly in place.
Professional fitting is recommended if you are not confident working with bonded body parts.
Use the vehicle lookup on our site or check the Vehicle Fitment tab for full details before ordering.
Triple R Composites UK Authorised Installer & Distributor.

