Will this interfere with my trunk lid when it opens?

No. The A Spec wing profile is designed to sit above the hatchback glass and clears the panel movement. Install at the factory mounting points and you'll have full clearance during normal operation.

What's the mounting hole pattern, and will I need to drill into my roof?

This wing uses factory roof mounting holes — no drilling required. Verify your roof hole locations match the wing's pre-drilled pattern before final assembly. A quick visual inspection will confirm fit before you commit to fasteners.

How stable is this at highway speeds?

FRP wings mounted at factory points are designed for highway stability when properly fastened. Ensure all fasteners are torqued to your vehicle's service manual specifications and check them after your first 100 miles to confirm no settling has occurred.