Serious Problem

I have a 2002 Cavalier, I was driving, then went on the highway, as soon as i hit 80km/hr or 49.71M/hr there is a lot of vibration. The steering wheel and the speedo needle shake, the wheel moreso. It gets worse as I go faster, this never happened before, what could be wrong, what could i do to fix it?
thanks for ur help

take your tires and get them checked they probably need balenced. If you have ever seen them little weights on your rims that the clamp on, those help eliminate vibration at high speeds. also you might want to give your lug nuts a little tightening (but dont force them)

Well since your city is listed as Regina, I would take a guess and say Canada. I live in Ontario and it happends to me all the time. Its probably ice/snow inside your rims. The littlest bit will throw off your allignment. get under the car and clean it all out of your rims.. you will be good to go.

It could be a balance problem but its as bad as you make it sound I would definatly check the tires, you might have a broken belt. just look for a bulge or indentation no the side of the tire.