Does draining the radiator also drain the "fill tank with the cap on the passenger fender-well"? To refill, just pour coolant into this tank until it fills the radiator and this tank. It appears that there are electrically controlled valves in the coolant lines between these two pieces? In my other cars I would call this fender tank the overflow but in this case is it part of the radiator, as far as filling and draining are concerned?