Car won't shift from reverse to a drive on my 2015 mercedes benz s550.

Hi! This is Bo with Car Genius at RepairPal! Well, that sounds frustrating! There might be an issue with the transmission linkage or the transmission control module. When you try to shift from reverse to drive, the transmission may not be receiving the proper signal and could even be an issue with the transmission itself. If you have any other questions feel free to call us at 877-913-1554! We'll be happy to find you a certified shop in your area!