In a day to day ,real world driving situation what are chances that an a BMW M5/6 ,Audi RS6/7,CLS/E63 or Turbo S are going to meet at a stop light for a drag race? Very unlikely isn't it ? Chances are that these cars in the real world are going to meet on the highway in rolling start .
Depending on where you live, this type of situation is just as rare.
This also depends on how long or fast you can open the throttle. I know where I live the heat will be on you pretty damn quick! (thay like to hide under bridges and such, places where you would never suspect) so long
strides up to 150mph or so will definitely land you in some big big trouble. Short Power pops up to 100 (maby 120mph) from 50-70mph is about ok. I have done it a few times in different vehicles without problems. You better be willing to slow down just as fast as you start around here.
I have not seen what the M6 (CP) can do yet. In a short power burst, in a run with the norm M6 GC, Porsche Panamera TurboS, M5, exc, my money would still be on the Audi RS7.