Firstly, I had no problem with the existing system, including spawn camping. Just part of the game IMHO, even though in AH2, I always preferred maneuvering tactics and going for elevation to lying in wait. Meaning that I wasn't a big spawn camper.
But if you must change it, what's wrong with reverting to no walls, and allowing spawning GV to face either forward or back (like a plane on a runway)? Problem solved (especially if you up a Tiger II).
MH