Will this lip interfere with my trunk or bumper fitment?

The rear diffuser mounts to the existing lower bumper structure. Before installation, verify clearance between the lip extension and any factory trim or luggage rack you plan to use. If you're upgrading the rear bumper, test-fit both pieces together to confirm alignment.

Can I drill mounting holes, or should I use adhesive?

FRP panels can be drilled cleanly if you support the underside during the process — use a backing board to prevent stress fractures. Alternatively, high-strength automotive epoxy works well if you prefer a non-invasive install. Choose based on your comfort level and whether you plan to remove the piece later.

How stable is this at highway speed?

Proper mounting is key to stability at speed. Ensure every attachment point is secure and that the diffuser sits flush against the bumper with no gaps or flex. If you drill holes, use stainless or coated fasteners to prevent corrosion, which can loosen fittings over time.