@Saxy, The Older E63 M6 never reached 207Mph, That is only a SPEEDO readout...Its true top speed was under 200Mph, 194Mph if I recall from that same video, It also had a Cd.31, Which if anything is probably slightly better then your average Automobile, A Celica or Avalon has the same..The cars slippery, But that's nothing to shout about.
The New F11 M6 has more power, and is better geared, But its Frontal area and/or cross section is practically the same along with the same, or slightly worse Cd, at .32 or .33.(Last E39 M5 was Cd.29..) But that's also a claim. It may have aero, But it also has one Big thing, Weight, And 4100Lbs is Not light nor would it help regarding any form acceleration.
And as DeDe said, the Car had 640Bhp in the NON Competition form(15Bhp more then normal)(So lets just say 655Bhp(647Ps)), So that could explain its very fast 0-300Kph time, Im basing all my times on the "Claimed" Bhp figure of 575Bhp.
And by using the claimed Bhp number of 575Bhp, I expect its top speed to be no more then 208Mph, Don't know the gearing down to the number, Nor can I see a speedo or Gps run of the speed, But I will say this wont to past 210Mph at its ABSOLUTE maximum, So ill stick with 208Mph.
Pretty soon we will be seeing an E63 going as fast as an Enzo in the upcoming test..