Do these need any wiring work, or do they plug straight into the factory harness?

These are designed as a direct replacement at factory mounting points. Test-fit first to confirm your factory harness connector matches the marker plug — if not, you may need a small wiring adapter, but drilling into the bumper is not necessary.

Will these work if my car still has the original halogen side markers?

Yes. LED markers are a direct swap-out replacement and will work with your factory wiring. The LED draws less power than the original bulb, so no load issues.

Can I return these if they don't fit once I open the box?

Contact ModSupply's support team with photos of the fitment issue. Returns are handled on a case-by-case basis within the standard window — keep all original packaging.