Will this interfere with the hood or trunk seal?

No. The lip sits below the lower bumper line and does not contact the hood or trunk. Once mounted and painted, verify clearance by opening and closing both panels through their full range.

Does this require drilling, or does it use adhesive?

This lip uses factory mounting points and bolts to the existing bumper attachment areas. No drilling or adhesive required — fasteners pass through to the OEM holes beneath the bumper.

Will this stay stable at highway speed?

Yes. Once bolted securely to the factory mounting points and fully cured after painting, the FRP panel remains rigid at speed. Ensure all fasteners are tight and that paint has fully hardened before driving.