Will this interfere with the trunk seal or weatherstripping?

No. This is a front lip component mounted to the lower fascia and does not contact trunk seals. Verify clearance between the lip edge and any existing bumper trim or under-panel components before final installation.

Can I install this with adhesive, or does it require drilling?

FRP lips work best when secured through factory or new mounting points using mechanical fasteners for long-term stability. Adhesive alone is not recommended for this application. Confirm existing mounting holes on your bumper assembly before ordering.

How stable is this at highway speeds?

A single-piece FRP lip is designed for aerodynamic stability under normal driving conditions. Ensure fasteners are properly torqued and check them periodically for looseness, especially after extended highway use. Refer to your vehicle's service manual for fastener torque values.