Will this wing stay stable at highway speeds?

Yes. The single-piece carbon fiber construction provides the rigidity needed for high-speed driving. Bolt it down securely using the factory mounting holes and inspect periodically to confirm fasteners remain tight.

Does this wing interfere with the trunk lid or hatch?

No interference with normal trunk operation. Verify clearance in your specific application by measuring from the rear edge of your trunk to the back of the spoiler before final installation.

How do I care for the carbon fiber finish?

Wash with mild soap and water; avoid abrasive pads or solvents. The clear coat protects the weave from UV exposure. If the finish shows wear over time, light polishing with a carbon-safe product will restore clarity.