Will this lip interfere with the trunk seal or rear bumper fitment?

No. The front lip is mounted to the front bumper only and does not extend rearward. Clearance with the trunk or any rear components is not a concern. Verify the front bumper attachment points are in stock condition before installation.

Should I use adhesive or drill through the factory bumper to secure this?

This lip is designed for factory mounting point integration without drilling. Use the existing bumper fastener locations for a clean, reversible installation. Adhesive is not required if the mounting points align; fasteners provide the most stable long-term hold.

How stable is this at highway speeds?

FRP lips are designed to withstand normal highway air flow when properly secured to the bumper. Ensure all factory mounting points are tightened and the bumper itself is in good condition. For high-speed track use, verify the lip edges are finished smoothly and fasteners are checked regularly for vibration loosening.