Will this diffuser scrape on driveways or steep inclines?

The C Speed profile is designed to add visual aggression without extreme ground clearance loss. Verify your vehicle's current rear bumper clearance and compare to the diffuser's extension before installation. If you already scrape occasionally, this will lower your tolerance slightly.

Does the diffuser provide real downforce or is it mostly cosmetic?

C Speed geometry is functional — it's engineered to generate legitimate rear downforce through airflow management. That said, real-world gains depend on your driving speed and aerodynamic balance with your front end. You'll see measurable benefit on track; street feel is more subtle.

What finish should I apply to the carbon fiber?

Sand and prep the surface before applying your chosen finish. A UV-protective clear coat is strongly recommended to prevent oxidation and maintain the weave pattern's clarity over time. Matte or glossy topcoat choice is yours.