I have been to other countries and seen such programming of these cheap keys. The most raw method is pretty brutal as it encompasses removing the two processors in the EIS and reading the data off of them.

the more upscale systems use a special key with goes into the EIS reciever and pulls data from there. (saw in UK)

In european countries mercedes benz are like fords and chevys, you get all sorts of customers, e.g. white van owners to taxi drivers to garbage truck companies - such look for lower cost solutions. In the USA mercedes benz are sold as elite cars only and the market for such keys is not quite there.

if you ask abt why elite? - thats the reason you dont see mercedes benz branded garbage trucks in the USA, regular benz customers wont like that.

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2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)