Will these fit a 2013 S550?
 

mbworld.org/forums/wheels-tires/537173-new-19-amg-wheels-tires.html

Without spacers etc.

As long as the offsets are as stated at 35mm front and 48mm rear they should be fine. The rears will look a little "tucked in" since they're 5mm closer to the strut, and the stock S Class offset at 43mm already looks tucked in as it is. You may want to pick up some 5mm HR Trak spacer and lug bolts, which would be a very thin spacer and put you dead on the factory S Class offset. Or verify that presently you have at least 5mm of extra clearance between the top of the back of the wheel and the strut.

I avoided spacers myself forever and then finally caved and went 20mm rears and 15mm fronts on my OEM 20's. Huge difference in appearance and not a bit of trouble with vibrations or anything, so my fears were unfounded, and these are huge spacers, especially the rears.

Personally I'd do 15mm rear spacers not for clearance issues but for cosmetic reasons. That would put them sitting at about the same position as the fronts and give you a nice, wide stance and fuller looking wheel wells.