Will this interfere with my trunk seal or undercarriage at speed?

No. The Waver profile is designed to sit flush with the existing fascia line. Before installation, verify your vehicle's bumper-to-ground clearance and confirm mounting hole alignment with your OEM fascia.

Does adhesive or drilling secure this lip?

This piece mounts using factory-style fastener points. Use stainless hardware to prevent corrosion, and ensure you sand and prep the mounting surface before final installation for a solid bond.

What prep work is required before painting?

Sand and prep the surface with appropriate abrasive media, then apply your chosen primer and topcoat. FRP takes paint well — allow proper cure time between coats for the best finish.