Today, i was driving like 120 and i started to rock back anf forth

Yea today I was doing like 120, and i noticed my car rocking back and forth, I think the wheels are not balanced. What else could it be?

road not ment to be doing 120 and uneven pavement?

Do you have the same tires front and rear.

I had some 60 series tires on the back of my probe and 50 series on the front and at a certin speed I would get a very subtle rock from side to side from the rear. Not scary though.

Same all around