Will this interfere with the trunk seal or door gaps?

No. The front lip attaches to the lower fascia and does not extend into the door panel or trunk area. Once installed, it sits flush with the factory bumper line.

Can I use adhesive instead of drilling, or do I need to drill through the bumper?

This lip uses factory mounting points and is designed for bolt-on installation. You will not need to drill through the bumper fascia — fasteners attach through existing OEM holes and tabs.

Will the lip remain stable at highway speeds?

Yes. The single-piece construction and factory mounting points provide rigid support. Ensure all fasteners are torqued securely before driving, and refer to your vehicle's service manual for correct fastener torque values.