i've noticed that running soft tires on the track, they get so gummy that they pick up chunks of rubber that are laying around the track surface. after each track day, i'd get noticeable high-speed vibration (at 80+), which would go away in a couple hundred street miles, especially if i take a rough file and remove the biggest 'cling-ons'. i'm assuming this is normal, since i've gotten this with two different types of tires on two different cars. anybody with similar experience?