Do these plug straight into my factory fog housings?

Yes. They're designed as a direct fit—no adapters or modifications to the housing. Slide them in and secure with the mounting bracket provided.

Where do I mount the switch?

The switch mounts anywhere you can reach it easily. Dashboard, A-pillar, or lower fascia work. Just run the harness neatly along existing wire runs and secure it with clips.

Will these work with my factory wiring, or do I need to tap into the battery?

The harness connects to your existing fog light wiring. If your factory harness is damaged or missing, you'll need to run a dedicated line from the battery through the switch—standard relay circuit. Check your owner's manual for factory fog light routing first.