One problem related to side/rear glass has been reported for the 2003 GMC Sierra 1500. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2003 GMC Sierra 1500 based on all problems reported for the 2003 Sierra 1500.
Truck was parked outside at work during the day. When I entered the truck and closed the driver door to leave, the rear window exploded when the door closed. I am not aware of any objects hitting the window prior to this, or defects, etc. Contacted local GMC dealer who claimed to have no knowledge of this and therefore did not offer any assistance. It is being repaired at a glass shop at my expense with a new window.