this is an old issue, but the problem has finalled cropped up on my 05 so I was searching the forum and found a thread on the switch problems and then this reference to a Mercedes part number.

Back in 2009 Tom Vroom wrote "Now for some really good info....take the housing to your local MERCEDES DEALER as they are the ones that make the housing P/N A1934600104 and the price....are you ready for this....$136.00 plus tax. (Chrysler wanted over 300.00 for this same part!)

This looked real promising until I called the dealer. According to our local Benz dealer, this P/N A1934600104, is not a valid part number. The part in question is for the ignition lock assembly (not the tumblers, but the housing etc).

Any ideas on alternate part numbers? parts manager wanted the VIN number for my car but chuckled when I said it was a Crossfire, not a Benz, so it probably wasn't in his system. The Chrysler part number I have is 1-68001655-AA but haven't been able to get a cross reference for it.

Obvously, the need for the MB part number is I have short arms and deep pockets, and don't mind saving a couple hundred bucks.