All Mercedes have a key fob in the dash.
If you want keyless go they just put a silver button in the ignition slot. It is literally a removable button that replaces the key. The entire setup is a joke!
If you want to piss off a Mercedes owner walk off with his start button!
2014 Porsche 911 Turbo S
2015 Mercedes-Benz C300 Sport 4MATIC