I bought these off a recommendation from fellow BMWCCA members as well as the other Tire Rack reviews. Let me start off by saying that these made it a completely different car! I'd had the Bridgestone RE050A Pole Positions on my stock 19 wheels, and combining those with my Hawk Blue brake pads at the track, I was constantly outbraking my tires. Now that I've changed to square sizes, as well as switched to the Michelin, I'm getting faster lap times, and finding a lot more grip into the corners. I've got one track weekend and about 2500 miles on these so far, and I'm super impressed!