Unless it's something loose underneath I havn't checked yet. But after you drive the car for 30 minutes or so something starts vibrating from the back of the car. It's strange because it only happens after its been driven for a bit. If you start it up and go right away no noise. Any possible ideas? I'll check the exhaust out but I doubt thats it. I was just at Byron too. I launched it hard once but I was on street tires and just spun.