Will this wing stay stable at highway speeds?

Yes. Three-piece construction with proper support brackets is engineered for high-speed stability. Verify all mounting points are torqued to spec per your service manual before driving, and the wing will maintain its position without vibration or flex.

Does the trunk lid close normally with this wing installed?

The ZL1 V2 profile is designed to clear the trunk when closed. Before installation, dry-fit the wing assembly to confirm no contact with your trunk or rear glass, and measure clearance at the widest point if you've modified the rear end.

What prep work should I do before mounting this?

Clean the mounting surface on your existing spoiler bracket with a degreaser and allow it to dry completely. If you're bonding to bare carbon or fiberglass, sand lightly and wipe away dust. For the best result, reference your vehicle's OEM mounting hole pattern and fastener spec before assembly.