I have a Becker Grand Prix radio that needs to be replaced. I have found a used replacment Becker Grand Prix from a 90+ 300E. I also have heard that the wiring on all Mercedes cars for the radio is a little different after 89 because it has a extra feature that will leave the radio on until a door is opened. MY CAR IS A 86' 420 SEL, WILL A NEWER STYLE RADIO PLUG IN PERFECTLY TO MY EXISTING WIRING ??? WHAT YEAR DID THE BECKERS GET CODES INSTEAD OF BATTERYS ???