You could always put your stock wheels back on and see if it goes away. That way you can at least eliminate one variable.
Most vibrations on low mileage cars are usually just a simple balancing issue, but in this case you said it's already been rechecked. Second most likely cause is the wheel is out of round. Third most likely cause is your tire is flat spotted or defective.Hi guys, I recently bought a set of 20" Forgedstar's as street wheels. The car had light vibration after 80 mph. Then I had ACG San Diego rebalanced the wheels again, then now it becomes severe. Since they have balanced twice, I guess it wouldn't be balancing issue? Here's the symptoms of vibration:
1 any speed after 80 mph
2 braking (the car feel like falling apart during hard braking)
3 a metal to metal rubbing sound from rear (I guess this is more like a brake issue?)
What should I do to fix it? Any help would be appreciated.