Call me thick but the basics of all of this if I understand it right is that cars which are on the line are performing and handling like they should, cars below the line are better handling cars (as this formula is based on an average power/weight vs handling) and finally cars which are above this line aren't as good a handling car as they should be.
If this assumption of mine is right then with the exception of the 335i, CSL and the Z3 all the other Beemers aren't performing as we would have hoped.
Bummer.
Here's hoping the new M3 lives up to expectations.