Ok, I just had an idea for making trenches, fox holes, and sandbags bunkers. Why not make bunkers like we would a static vehicle? I don't know if its possible to set up a unit to be able to use his own rifle from a vehicle, but I know you can use vehicle mounted weapons right? So all you need to do is make a static trench with perhaps a MG position and several other trench 'passenger' locations in it where players would 'get in' the trench.