Driving down the road, all needles where they should be, red coolant light
comes on. Stop the car, check the fill/overflow tank. It's up to the top
mark. Next , empty the baggage area, raise the engine hatch lid. Removed
the expansion tank top, found coolant to be below the sensing prongs on the
sensor, thus the flashing red light. Topped off the tank to get home. No
more red light. It was dark, so must wait to tomorrow when it cools off to
see where the coolant  went. But I could see there were no coolant leaks.
So the question is - where did the coolant go.

Ideas??

John