Will this diffuser scrape on steep inclines or driveway angles?

The Speedster design maintains a relatively subtle extension. Before final installation, dry-fit the panel and check clearance at your vehicle's lowest points—driveway approach angles, speed bumps, and parking ramps. Your specific ride height and suspension setup determines actual ground clearance.

Does dry carbon need protection or will it yellow in the sun?

Dry carbon is UV-stable as-is, but applying a quality clear coat will preserve the weave color and add hardness against road debris. The choice of clear coat—gloss, satin, or matte—is yours; this lets you match your overall finish strategy for the rear bumper.

Is this functional aerodynamic or purely visual?

The Speedster profile is engineered to improve rear-end flow and downforce characteristics. You'll feel the benefit most at track speeds; at street speeds, the visual impact is the primary statement.