The coupé just appeared on the belgian mercedes site.... BUT
the sleekest version listed only has a Cd of 0.26... and most versions have 0.27
pretty good in the real world but a bit disapointing.... likely the coupé doesn't come with certain trim options wich would give a little lower drag maybe
so 0.24 certainly seems possible in a slightly lowered version with a smaller engine that allows the actuall grill to be reduced a bit furher and skinny tires.
to soften the blow, here a topview drawing...
