Complete Olga parked in a barn that was converted into a base ( built 3 walls inside and one was a gate with locking combo.)
Logged out for about 12 hours - when I logged back in car gone but base was fine and door locked. This was literally the first and only day it was sitting there. Didn't even last 24 hrs. Our server resets 2 times a day both at 12:30
Private server name: The Fatherhood

Other users have said their cars have despawned when parked on road but stay for weeks parked on grass.