Actually an S204 2008 C200k. Had a new battery fitted two weeks ago. Drove the car for 350 miles on Wednesday. Went to start it today, the remote opened the car, the mirrors folded out on opening the door. Put the key in the ignition and nothing. No handshake noise, no warning lights on position 1 and nothing when trying to start the car. Tried turning on the headlights - nothing. Tried attaching a booster pack to the connections near the battery - nothing. Same with both keys. Does that suggest the ignition switch? I have noticed a whirring noise on opening the car since the new battery was fitted but today is the first time I've had this problem.