"Probably because when you leave your vehicle, you put your forces ID card in your pocket and don't leave it on display in the window like a car pass, so the car can be seen to legit. No car pass in a car at BZN, but driver has an ID card in his pocket at MPA, is not a lot of use to the security forces"
And? How does the car get there? Short of someone having invented a pegasus powered mondeo while I was having dinner, presumably the vehicle has to pass through a security gate where it is checked by the ever-vigilant guard service? Would a MOD wide vehicle database be difficult to organise, just for the once-in-a-lifetime occasion that someone questions the ownership of a parked car?