Had a problem in which I could not turn the key. Had to have my 300sd towed. The mechanic indicated that it was a problem with the ignition core. I had it replaced. On the way home from the repair shop I stopped off at Costco. It was locded up again! Called the mechanic who informed me that it was some sort of pin in the steering collum. He wanted to charge me another $300. I felt ripped off. I've just been leaving the key in the ignition. I saw an item on e-bay which was an igniton core and a housing. Sort of a T shaped housing with a pin. Is this the item I need? Any problems with getting a used item? Any help would be appreciated.