After many years of performance driving on the street, I've had a revelation. Today's tires are so good, suspensions are so good, and performance parts are so good that--unless you intend to track your car--you should leave it stock. Moreover, forget summer performance tires and get all season tires, which ride much better. Some guys I know, here in St. Louis, are even buying 'crappy tires' on purpose. Why? Interesting story. Two years ago, I drove a new ND and was totally underwhelmed by the handling. Huge body roll. What was going on? What was Mazda thinking? I went to the Fiat dealer and the 124's were MUCH better handling. I bought one. Two years later, I realize that Mazda is much smarter than me. They recognize that modern tires/parts are so good that you can come nowhere near the limits of a modern sports car on the streets. They designed in the huge body roll ON PURPOSE. I've come full circle and I now have no interest in improving the handling. I WANT the car to roll, I want all four wheels to slide. You can test your limits, and the cars, at safe speeds. It's not about ultimate speed--that's for the track and why they use stop watches there. It's about FUN. And you can't experience that if the car is just going fast, with no drama, and not much input on your part. I sold the Fiat ND to Carmax (for $5000 more than I paid for it) and bought a low mileage, one owner NB, with every receipt from new. I'm VERY happy with it.