It's the weirdest thing. My coolant level warning light comes on with headlights or parking lights, goes off with the parking lights off.

EDIT; The coolant level was actually low. I topped it off. Light still comes on with park lights.

EDIT AGAIN; The warning light was not coolant level. It was the bulb out warning light as it was coming on with the lights. One new bulb later, light is out.

This is gonna be a good one. Although I think not related, my ABS BAS ESP lights came on today too after a hard braking.