Left back up lens 04

 

GM does not sell the lamp separately from the finish panel. List price on the finish panel is $680.20 (part #1920-8231). I would try a salvage yard first, although I'm sure they would try to make you buy the complete panel assembly with lamps. Maybe ebay?

 

Yea the salvage yards sell it the same way. I just found one on eBay for 65 Bux shipped. Hopefully it's useable. Thanks