Will this lip interfere with the factory trunk seal or undercarriage?

The two-piece design mirrors OEM geometry, so trunk clearance is maintained. Before final installation, hand-fit both pieces to verify no contact with existing bumper hardware or weather stripping on your specific setup.

Can I use adhesive instead of drilling through the bumper?

FRP parts are typically best secured mechanically (bolted) for long-term durability and to handle vibration at speed. Adhesive alone may not provide the clamping force needed on a front lip exposed to wind load. Plan on fastening through the factory mounting points or drilling pilot holes as recommended by your install guide.

How stable is this at highway speeds?

FRP is rigid and won't flex or rattle once properly fastened. Ensure all fasteners are tight and verify the lip sits flush against the bumper along its entire length before extended driving. A solid mechanical bond will keep it stable even at sustained speed.