20 years as a mech. had to take car under warranty to dealer "the gods of cars" .for one they look at you like you are the biggest moron. one issue was the a/c compressor runs constantly with selector on floor without a/c button depressed ,turn to vent comp. shuts off ,dealer says its normal .all my other cars "gm" do not do this .i went across to used car lot of same dealer looked at 2 other 07'cobalts they did not do that. DOES SOMEONE HAVE AN IDEA?