Do I need any additional wiring harness or relay kit to install the switch?

The switch is pre-wired and ready to splice into your vehicle's electrical system. You'll need basic crimpers and electrical tape—no separate relay kit required unless you're running auxiliary power upgrades.

Will these fit into the factory fog light locations without modification?

Yes. The bezel trim and housing are designed to use factory mounting points. No drilling or cutting needed—they drop into the stock openings.

Can I swap out the H11 amber bulbs for a different color later?

The sockets accept standard H11 bulbs, so you can upgrade to different wattages or colors once installed. Just verify compatibility with your local road laws before switching from amber.