Will this diffuser scrape on steep driveways or inclines?

The diffuser extends beyond the rear bumper line, so approach angles matter. Inspect your driveway grade and typical driving routes before installation. If you frequently encounter steep ramps, measure the lowest point of your current bumper and compare it to the diffuser profile to confirm ground clearance at your typical approach angle.

Is this functional downforce or cosmetic?

This is a J Spec style diffuser—primarily aesthetic. It captures the aggressive rear-end look without active aerodynamic function. The visual lines and depth are the design point; any airflow benefit is minimal and not engineered as a downforce component.

Should I apply clear coat, or does it arrive finished?

The carbon fiber arrives uncoated. A UV-protective clear coat is recommended to preserve the weave pattern and protect against oxidation over time. Sand and prep the surface before applying your chosen finish, or install as-is if you prefer the raw carbon look—both are valid approaches depending on your garage aesthetic and climate exposure.