Mercedes Benz units are paired to the vehicles electronic key system thus they will only ever work in that vehicle.
Once removed they lock out until they are refitted, there isn't a way around this as every Mercedes Benz has its very own Electronic Ignition Switch
with its very own code, only Mercedes Ben in Germany know this information.
If Mercedes Benz can do this then why can't Audi!!!!
This is the main reason why I won't buy an RSN-e unit!