In Arma 3, one can assignAsX (driver, cargo, etc), unassignVehicle, get assignedVehicle for a unit
addVehicle and leaveVehicle for a group
but one does not have a way to get which vehicles are added to a group.
assignedVehicle <unit> (we have)
assignedVehicles <group>/groupVehicles <group>/getVehicles <group> (I wish)