Will these mount at the factory fog light openings without modification?

Yes, these are designed for factory mounting points. No drilling or cutting required — they bolt into the existing locations.

Do I need additional wiring or will this integrate with my RAV4's electrical system?

The switch and harness are included, but integration with your vehicle's factory wiring should be confirmed during installation. Have a wiring diagram or service manual handy to ensure correct connections to your vehicle's electrical harness.

If the bulb burns out, is it easy to replace?

H16 bulbs are standard and widely available. Replacement is straightforward once you know how to access the housing from your RAV4's engine bay — refer to your service manual for the exact removal procedure.