i lost a tire in a shifter kart once, way scarier than in a car.my steering wheel shook like crazy going 50+..found out i had a loose tire about to come off.
x2. i have this problem all the time because i drive on gravel roads. my car is a fwd and its only the back wheels that get build up in them.Check for build-up on your wheels. I had the problem earlyer this year, took it off, and cleaned it out, worlds of difference. They may be balance but the buildup throws it off, easy, and cheap problem to fix...
Jon