KEYLESS-GO
On vehicles equipped with option code (889 - KEYLESS-GO) you do not need to remove the SmartKey from your pocket or handbag to unlock the car. Simply grab the door handle and pull to unlock and open the door. To lock the door close it and press the knob on the door handle. To start or stop the engine hold brake and push the "start/stop" button on the gear selector
The vehicle can still be operated with the electronic key which then has priority over the KEYLESS-GO card.
Credit card type keys were used in pre-facelift vehicles after which MB integrated the card in regular looking SmartKey. You cannot tell the difference between KEYLESS-GO key and standard SmartKey by looking at it. However, KEYLESS-GO key has 1 battery while standard keys has 2 batteries.