Here I am again, really hoping I could change my user name. I drove my Acadia to another town about 60 miles from home and back today. Took the interstate driving about 70-80 mph. The trip there was uneventful with the exception of a little sluggishness at about 65-70 mph. I haven't taken the time to learn about those extra gears! The landscape was fairly flat all the way. On the return trip, it was raining pretty hard. I had to use the defroster to keep the fog off the interior windows. It was about 40-45 degrees outside. Anyway, the heater fan would turn itself up and down like it wasn't getting power. The actual air would be warm then cold. (It was not set to "auto") My 30 year old daughter tried different settings, but the darn thing would change itself from hot to cold. When I pushed the AUX button, it would blow cold air to the passengers in the rear. The unit would actually keep turning the air conditioning on itself. It would switch from one setting to another even when it was not set to "auto". When I got closer to home on the return trip, I also noticed it was smelling like burned plastic or rubber inside the car. I have brought this to the attention of the local service department, but they were "unable to duplicate" when they had my car. I have been home for 3 hours and I just decided to go out into the garage to see if the seat warmers were working, just to check the electrical. I did not actually start the car, just turned the ignition to auxillary so that may be the reason they did not work. But as I walked in front of my car to go back into the house, heat was coming out the grill. The hood was warm to touch 3 hours after the car had been sitting! My garage is not warm and it is 40 degrees outside. The gauge on the dash still indicates my engine temp to be 210....good old 210! I don't know if the rain got the fuse box as others have stated is a problem or what. I am now at 3400 miles...what next? I was supposed to be taking my daughter back to her home this weekend, a 600 mile trip...don't dare take this POS that far away from home on a holiday weekend! GM, are you listening?????