I did the Mountune springs and a good set of summer tires. I find it perfect for the 99% street/1% autocross use. I got rid of the tall factory ride height, stiffened the springs just enough to balance out the factory dampers, and took out some of the pitch/roll. I can't get anywhere close to exceeding the level of grip on the street with this setup and the ride quality is very good on poor quality roads. I noticed that the rally school made a huge difference on the street as well, mostly in the winter and in the wet. It is more about proper techniques, eye control, understanding what the car is telling you, and how to shift weight around the car. Those lessons work all the time. In the 20 years of messing around with suspensions, I have found that throwing parts on the car typically just masks a driver issue.