Ooooo . . . good theory about the overheating!

It would kind of make sense that it would overheat when we start driving, and then cool off when we come to a stop light . . .

I will definitely be looking at the filters tomorrow. I am guessing that they have never been replaced as the car only had 25000 miles on it when we bought it 6 months ago.

Thanks for yor help!
Bryan