Will this diffuser clear the ground on steep driveways or parking lot approach angles?

Confirm the diffuser panel height against your vehicle's current ground clearance and typical approach angles at your location. FRP is durable, but striking pavement will cause damage. Measure your rear bumper's lowest point and compare it to the diffuser extension before final installation.

Does this diffuser function as active downforce or is it cosmetic?

This is a cosmetic diffuser designed to enhance the visual profile of the rear bumper. It does not actively manage airflow or produce measurable downforce. The LBW style adds perceived depth and aggression to the rear end.

What prep work is required before painting?

Sand the surface with appropriate grit, clean away dust, and apply your chosen primer and color coats. The FRP surface is receptive to standard automotive paint preparation. Refer to your paint manufacturer's guidelines for adhesion promoters or primer selection if needed.