Not gona be relavent to you but i thought id throw it in for interests sake..
Was driving my sw20 back to work on wednesday and got viscious vibration between 80-100 (like 4 times more intense than you average unbalanced wheel)
i pull over.. no flat tire... figured it was the balancing so i start again... intending to drive to my balancing place, it happens again but even worse...
So i pull over suspecting i must have a wheel thats about to fall off... i looked at each wheel and found nothing wrong except for a little smoke coming from the right front... the caliper had seized.... (bloody turbo was pushing it along)... i touched the wheel (factory skyline mags) and it was almost too hot to touch... i hate to think what temperature my disc was... $150 later and a rebuilt caliper