I'm really hoping this is a dumb question but check out these pics and tell me that that isn't a missing bolt (trans mount?). I had this trans replaced about 2 months ago under warranty the shop has been so bad with attention to detail. I've been back 3 different times for my battery being loose (car wouldn't start), sway bar loose (huge clunks when turning), now I've noticed random noises coming from the front of the car. I went to look around and noticed the 1 O'clock positioned bolt was missing, along with that there are also 2 other bolts that seem to be missing in the 2nd picture. Not entirely sure about those two but my guess is they shouldn't be bolt-less. Unless they made extra bolt inserts...
If you see something about "man drives car through Utah GMC dealership", it wasn't me...here is a link, it's legit no worries.
Dropbox - Photos - Simplify your life