Bren Gun Carriers. A lot of 'em about at the time. Can't see a sensible role for them in AH though, unless we get mortars/flamethrowers.
Maybe we could have 'convoys' of trucks and jeeps and bren carriers. If you get half of the convoy into a town then 10 soldiers can dismount from a truck and run for the map room.
Slower than using M3s but more robust.
Also, it gives everyone more soft targets to strafe and lets us use lighter weight weapons - like machine guns - instead of just cannons all the time.