Hello R230 (SL500) 2003.Recently I very foolishly left the car in the garage after stopping the engine with the key in. Result very flat service battery and starter battery down to 10.5 volts. Charged up both batteries (with the service battery earth disconnected) and car came back to life. However initially the key I left in ignition although it would unlock car and turn electrics on would not start car . Now ( despite renewing its 3v battery) it will start car but gear lever is stuck firmly in Park. Our other key (the original) and key-card work fine and car is back to normal. Any ideas?