a couple of months ago, i bought so2 pole positions (thru tire rack) for my '98 540i/6 speed. loveED (past tense) the tires, but after a couple of months of street driving and 2 days of autocross, they are about toast. so, for autocross, i will be running racing tires, and for street i want a max performance tire (z rated) that is not so expensive. any suggestions? sumitomo? yoko? thanx, crop