Will this lip interfere with the trunk seal or bumper panel gaps?

The M Performance lip is designed to sit flush within the existing fascia profile. Verify fitment by dry-fitting before adhesive or drilling; check that the lower edge clears the bumper base by a consistent margin around the full width. Any gap adjustment should be made during positioning — the piece itself ships in final form.

Do I need to drill mounting holes or can I use adhesive?

This lip accommodates both methods. Adhesive alone works for stock bumper surfaces that are clean and flat; drilling through the FRP into factory mounting points provides mechanical lock if you prefer. Drill pilot holes in FRP first to prevent cracking, then into the bumper substrate. Choose your method based on your bumper's condition and your preference for permanent vs. reversible install.

Will it maintain fitment at highway speeds or flex under aerodynamic load?

FRP is rigid enough for highway stability when properly mounted. Secure attachment — whether adhesive, fasteners, or both — prevents flutter. Do a final torque check on any bolts after 100 miles of driving to catch any settling. The material does not flex under normal aerodynamic pressure at legal speeds.