Be sure to leave backdoor route so puma/p4 can drive in and snipe ambulance, thats a big part of usf faction identity.
Ever had a Penal in an M3 drive into your base and throw a satchel on your med bunker? It's just as tilting.
I agree the Ambulance should get like a 50% damage reduction when in the base sector, I'll add it to my 2019 wishlist for you.