Finally happened to me on the 400E. No warning, no signs of failure, car in parking lot, ignition won't turn.

Lucky for me, locksmith was able to meet me @ the car this afternoon. Apparently this is the most common thing he encounters and he does hundreds of 124 "key won't turn" situations. He ground off the lock cover & replaced lock cylinder, but looks like the housing is FUBAR as well as locksmith was still not able to turn key. What is strange is that the steering wheel is in fact not locked even though the key won't turn - I suppose this is b/c the housing needs to be replaced.

He's going to come back to the car tomorrow w/ a new housing, which he can and will install right there in the parking lot! Ring a bell for anyone?? I sure hope this fixes the issue as the car's stuck in a parking lot 35 minutes away until situation is solved.

If anyone needs a locksmith who's a Mercedes ignition dis-assembly EXPERT, PM me!