O.K. I thought it was from the play between my front/rear mounts and the brackets so I squeezed some of those rubber things on and reinstalled so there is no play but I'm still getting the vibration. I know you get more with prothane but this is NOT normal. It's when I'm accelerating and the only thing I can think of is my exhaust because I did it at the same time. It feels like a side- to- side shaking more than a vibration. Has anyone had this problem with Invidia?