You all have a burned-out shifter indicator light.
There IS A LIGHT in the shifter as part of the original/standard equipment.
Take-off the piece of carpet in the tray between the seats.
Remove one screw (in the middle) that holds the wooden piece.
Lift
Remove (pull-out) the black plastic shifter surround.
THERE IT IS, on the left side.
Pull-out from the connector
Visit your local friendly Benz dealer. Don't forget to bring about $1.99 for a new bulb.
Good Luck
Seriously, there is a light down there.
JackD