One problem related to back up lights has been reported for the 2003 Chevrolet Impala. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2003 Chevrolet Impala based on all problems reported for the 2003 Impala.
Purchased a second Chevrolet Impala with same defect with tail light compartment. Holds water indefinitely, not just condensation. I now have a 2003 and used to have a 2002 with same problem. Causes light bulbs to go out frequently and also alarm will go off when opening trunk which I suspect maybe a short in wiring due to water. I have contacted a local Chevrolet dealer's service dept as well as gm corporate and they are familiar with problem but no with no recalls yet to provide resolution of what I believe is a safey hazard when light bulbs continue to go out. Of course they want me to pay to replace defective taillight assembly that may still have some condensation problems.