Will this interfere with my trunk seal when the car is parked on an incline?

No. The front lip extends from the lower bumper and does not contact the trunk weather stripping or rear deck area. Your trunk seal operates independently of front-end geometry.

Do I need to drill holes, or does this use my factory bumper attachment points?

This lip uses factory mounting points — no drilling required. Align it with your OEM bumper's existing fastener locations and bolt down. Verify your bumper attachment hardware is intact before installation.

Should I adhesive-bond this or drill through the panel for extra security?

Adhesive alone is not recommended for a front lip that will encounter airflow and road debris. The bolt-on design with factory points provides the strength you need. If you want additional security beyond factory fasteners, consult your vehicle's service manual for approved drilling locations and fastener torque specs.