Do these mount at the factory fog light locations?

Yes. These use factory mounting points — no drilling, brackets, or body modifications needed. You'll bolt them into the existing bumper holes.

Will I need to run new wiring from the battery?

The harness taps into your vehicle's existing electrical system. Run it along the inner fender and up through the firewall to the switch location — standard practice, no custom relay setup required.

Can I replace just one light if it burns out, or do I have to buy the whole kit again?

H11 bulbs are a standard size and cheap to swap. You can buy a replacement bulb separately at any auto parts store and swap it in the housing yourself in under a minute.