Hi Beedub, I would not lower the car anymore than you need to for performance. The control arms should never be more than horizontal to the ground EVER because it decreases the camber and will actually cause more roll. That is why very low track cars run 1000lb spring rates. I can not type out large excerpts from suspension books to give you more info since I am typing on my phone. I have attached a good read from a well known bmw, car geek.
http://www.e30m3project.com/e30m3per...t_transfer.htm
Dubsesd car is beautiful and looks great but will handle poorly unless the suspension points have been modified as they do to ALL dtm cars.