YOU NEED TO TELL YOUR SALES GUY THAT YOU WANT TO ADD SATELLITE RADIO. IT WILL COST ABOUT $800 INSTALLED BASICALLY THEY ADD ANOTHER ANTENNA AND A SMALL BOX BEHIND YOUR DASH THAT PLUGS INTO YOUR MCS OR WHATEVER THEY CALL IT ON THE NEW S CLASS. IF YOU HAVE A GOOD AUDIO SHOP AROUND YOU OR YOU CAN ASK YOUR SALES GUY LIKE I DID THEY USALLY CAN POINT YOU TO A PLACE THAT CAN BUY YOU THE PARTS CHEAPER, BUT I RECOMMEND HAVING THE DEALER INSTALL IT SINCE THEY DO HAVE TO REMOVE SOME STUFF TO INSTALL IT.