Unless every SVT out there was hit before they were bought then I don't think it's because of that. I think that's BS. I've never had any problems with Dean Sellers on 15 mile between Crooks and Coolidge. We've been taking cars there for years, and nothing too big to complain about. My car does the same as yours with the shuddering. When I'm in lower RPM's it does it, and then when i go to push the gas pedal, whether it be a little bit or push it hard, it studders some more before it goes normal.