There is not a 2 inch receiver available for your Mercedes, but you can still carry bikes if you install the Curt Class I hitch, part # C11828.
You could use an adapter like part # HTAD, but doing so will have its downsides. Because the adapter moves the load of the rack and bikes further away from the hitch, the leverage applied to the hitch will increase significantly. Because of that fact, using an adapter will LOWER the tongue weight capacity of the hitch by half, from 200 lbs to 100... view full answer...
I do have an option for you but we only offer the WeatherTech Side Window Rain Guards with Dark Tinting for a 2003 Mercedes-Benz S-Class (Long Wheelbase Models), part # WT80274 for front or part # WT81274 for rear. I don't have dimensions of these window guard unfortunately but so long as you have the long and not short wheelbase model I can confirm they will fit. view full answer...