Will this interfere with my trunk seal or bumper alignment?

No — this is a surface-mounted lip designed to clear the bumper body. Before installation, verify your bumper sits flush and square on the frame. If your bumper has been repaired or adjusted, confirm fit before final mounting.

Should I use adhesive or drill through the carbon fiber to mount it?

Drill-through is the recommended method for durability at highway speeds. Carbon fiber is strong but can separate under vibration if only glued. Use appropriate fastener locations on your bumper and reference your vehicle's service manual for mounting point spacing.

Does this need a clear coat?

A UV-protective clear coat is highly recommended to preserve the weave finish and prevent oxidation from UV exposure. Without protection, bare carbon can dull over time. Your clear coat supplier can advise on application method for carbon fiber surfaces.