I've seen three of these in the last year. Two were the lights, resealed them with GM sealant. The other was the body seams where the sides and roof skin meet. Water was coming in from behind the A-pillar covers. Sent that one to the body shop. Carfax showed no indication that it had been wrecked, and the body shop said it was from excessive flex. Probably due to a LOT of off roading. H@'s are really not meant to be rock crawling and such, despite what GM says.