if the front wheels lost a weight or are improperly balanced you will feel a shimmy shakin in your steering wheel as the speed increases,you will also feel it as you apply the breaks,this may throw you off thinking your rotors are heat warped,i doubt it,if the vibration is in the rear,you will feel it in the seam of your pants,have some one check/rebalance all 4 wheels,find someone who has a road force wheel balancer,it uses a metal roller then applied a forced load on the tire as it spins,this is the most accurate way to locate the exact location needind the weight,it will also tell you if the tire has a flat spot or a broken steel belt,this is just a few pointers,you may also notice the vibration reduces or greatens the slower or faster you go,most vibrations are from 65 mph-80 mph,good luck,but def get the tired road force tested.