That was a pretty neat video, I'll post it here for anyone who wants to see it:
http://www.viropop.com/episode/ZPR_20080116
Anyway, welcome to the site! It's sounds like you're doing pretty good, but there's always room for improvement.
Firstly, your cars are new, so go get yourself one of these:
Scangauge 
Are you interested in doing any aeromods? Yes, basjoos's car is the real deal, you will find it on the site in the aerodynamics section,