Mudfrog

Hey guys, A buddy of mine is selling a 2003 Tahoe LS. Sometimes the transmission will slip from 1st to 2nd, because of this he is selling it for a pretty good deal. I'm counting on just replacing or rebuilding the whole transmission for peace of mind. For the most part the body is in good shape with the exception of some bubbling around the lock on the rear tailgate. I have seen several Tahoe's in this year range with the same issue so I'm assuming it is a common problem on the east coast. Underneath there is some surface rust on the frame. Not a big deal as I can clean it up and repaint. My biggest question is where are the problem spots for body / floor pan rust. Before I commit to buy this thing I want to ensure underneath it is solid.