I also have Eibach Pro Kit springs on my car. I'm wondering if the lower control arm brace for rear can mess with alignment and cause vibration. I had the car aligned and balanced and just put new tires on. Could the vibration just be normal from the road and the fact that the car is lower to the ground?
The back end seems to be shaking a little, I don't know if it's in me head because I'm paranoid or if it's just the lower suspension causing more feedback through the car?? WTF?

Any help please...