My aftermarket one's RF and it rotates the code too, so there's a fixed code that serializes the car and a changing code and the car won't open if it gets the same code twice.For it to be possible it would actually have to be within a band that the WiFi controller can actually transmit on, and data it can modulate. Not all radio signals are the same, much like the way it's incredibly difficult, if not impossible, to get an IrDa device to transmit TV remote codes.
From a different aspect, opening the car is one thing, but a lot of factory fitted immobilisers don't respond to the keyfob's signal, only to a chip in the key itself, so even if you could open the Mercedes you probably wouldn't get it to start.
