I'd like to help you but something doesn't smell right here. Is the "expert mechanic" qualified to work on the MB Drive Authorization System on your car? It's not all that complicated as long as you understand it. The ignition switch, steering column lock, and the engine control module are "married" to each other. If any one is replaced, it's not as simple as plug and play! Also, why do you say the dealer techs' were fools? Just curious.