After an exhaustive search, I could night find any insight into a replacement for a cracked black plastic housing for the trunk latch on my '03 SLE. I tried to find it on rockauto.com and could not, and gmpartsdirect.com has a difficult user interface, but I tried and could not find it.
My bad - closed the trunk too hard once. Still works, no leaks, but want to be sure Bonnie has all the best. What can I say, I love her!
The original part number (25726744) changes up at least once. The newest number is 10376779. It shows at GMPD with a cost of $88.95. I do know there is no stock in Canada (not that you'd be looking here anyway).
I would strongly suggest trying a wrecker for this. In 2002, there were two versions. One had an emergency release handle and early production didn't. Late production 2002 (with the emergency release handle) through to 2005 are all the same.