Setup is as follows
328i
DHP
H&R sport
MPerformance Brembo's
Challenge SS brake lines
8.5x18 running Yoko Neova's 245 front 255 rear
Ran my first event on the stock runflats so needless to say a huge all-around improvement was found with the track wheel/tires. I also added the SS lines after my first event with the car and that further extended braking before ABS intervention.
aside from those obvious improvments I still consider myself a track newbie so I'm reluctant to point out the vehicles flaws...because the majority would probably be that of the driver