Will this interfere with the trunk lid or hatch operation?

No. The extension is designed to clear the trunk opening fully. Verify clearance after installation by opening and closing the lid several times before final tightening. If you've modified your suspension or added aftermarket wing supports, confirm the fit in those specific conditions.

Does this use the same mounting hole pattern as the OEM wing?

Yes. The extension is engineered to align with factory fastener locations, eliminating the need to drill new holes. Before installation, check that your OEM wing fasteners and mounting surface are clean and undamaged.

What prep is required before painting?

Sand the entire surface with appropriate grit to remove the mold release agent and create adhesion for primer and topcoat. Once sanded, apply your chosen primer system and finish. Reference your selected paint manufacturer's surface prep guidelines for best results.