Will this interfere with my trunk when it opens?

No. This under-spoiler is designed to mount low on the rear bumper and clears the trunk lid during full articulation. Verify mounting clearance by test-fitting before final fastening.

Can I install this without drilling into the bumper?

Yes. The diffuser is engineered to use the existing rear bumper mounting structure. Avoid drilling unless you're adding supplemental support, which may require hardware sourced separately based on your install preference.

What prep work does this need before painting?

Sand the surface with appropriate grit, clean thoroughly to remove dust, and apply your chosen basecoat and clear. Follow your paint manufacturer's prep guidelines for the best adhesion and finish durability.