Will this diffuser scrape on steep driveways or inclines?

The diffuser extends beyond the OEM bumper line. Before installation, verify ground clearance at your driveway angle and any speed bump transitions. Measure from the diffuser's lowest point to the ground and compare against your approach angle to avoid contact.

What prep work is needed before painting?

Sand and prep the surface with standard automotive preparation techniques before applying your chosen topcoat. The FRP surface accepts primer and paint well once properly cleaned and sanded.

Is this purely cosmetic or does it provide any functional downforce?

This diffuser is styled after RS3 design language and works visually as part of an aggressive lower-bumper package. Functional aerodynamic benefit depends on vehicle speed and overall body setup; treat it as a styling element rather than a performance component.