if an sl600/600sl has 16x8 wheels stock, then how can they not clear the calipers if the brakes are the same?

I think you should get a hold of luke @ tirerack and talk to him about it, He should be able to help you find the right size and for a good price too.

Alon

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'92 300CE - Sold
2004 C240 - 744 - C7 Wheels - Android Radio
2002 C320 - 816 - Sport Wagon - Sold
2006 E350 Wagon - 368 - Dead
2015 GL350 Bluetec - 197U