I think that it's called a TMV (Tactical Medical Vehicle?) or something, but it's on standby whenever flying takes place, along with a small team of medics to react to any sort of emergency to do with an aircraft at the airfield.
This one is on standby outside the Med Centre at Wittering, although there's not much flying going on – poor weather and lack of suitable diversions, I understand.
This one has its headlights on the sweet spot of the Fibonacci Spiral, by pure luck. I've only just found how to use the guide in Capture One Pro and it was in just the right place :-)
I was there only for admin; my flying category remains on hold while a medical snag is sorted out . . .