if (isServer) then {
  sleep 10;
  _vehicle = _this select 0;
  _units = _this select 1;
  _startPos = getPos _vehicle;

  countUnits = {
    _units = _this select 0;
    _i = 0;
    {
      if (!isNil _x) then {
        _i = _i +1;
      };
    } foreach _units;
    _i
  };

  if (typeName _units == typeName []) then { // list of units
    if (([_units] call countUnits) <= 0) then { // despawn
      _vehicle setPos (getPos vehiclePen);
      waitUntil {sleep 5; ([_units] call countUnits) > 0};
      _vehicle setPos _startPos;
    };
  } else { if (typeName _units == typeName "") then { // group var name
    if (isNil _units) then { // despawn
      _vehicle setPos (getPos vehiclePen);
      waitUntil {sleep 5; (!isNil _units)};
      _vehicle setPos _startPos;
    };
  } };
};