Will this interfere with my trunk seal or body gaps?

The lip extends the front fascia only; it does not affect trunk or door seals. Mount it at the factory hard points and check your fitment gap at the hood line before finalizing fastener torque.

Can I use adhesive instead of drilling, or do I need to bolt it?

This lip is designed to bolt at existing factory mounting locations. Adhesive alone is not recommended for front-end components that experience wind load and road feedback. Use the factory points for durability.

Will this stay stable at highway speeds?

Yes — when mounted securely at all factory hard points, the single-piece FRP construction is rigid enough for highway use. Verify all fasteners are tight before driving, and recheck them after your first 100 miles.