The other day I was riding in the city at about thirty miles per hour in my Sequoia with my little girl in the back. She rolled down the rear window an right away the car started to tremble all over as if you were in a chopper or somthing. It made the same sound as those old military choppers I used to ride when I was fling in the service. Anyone felt this. Any answers. Please help don't think I can live with this.