One problem related to defogger heater has been reported for the 2007 Chevrolet Impala. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2007 Chevrolet Impala based on all problems reported for the 2007 Impala.
1) new 2007 chevy Impala picked up 12/4/2006 with 6 miles on it. Heater worked when picked up. 2) drove car 12/5/2006 about 30 miles and heater did not work on freeway nor did fan, vents, ac, or heat. 3) problem not resolved yet. The next time I started the car after my 30 mile trip the heater came on when the ignition was started and the problem has not been seen again. I dropped it at a chevy dealer to evaluate.