So I flipped my car (XFG, if it matters) beside the edge of a track, right beside the wall. The drive wheels were still spinning, and the speedometer was showing some speed. I turned the wheels so they rubbed against the wall, and they stopped with the speedometer showing 0, and the engine stopping. Everything is fine up to this point. Now, I turned the wheels back to normal so they weren't touching the wall, and they magically sped up again to the speed they were at before, the speedometer was at the speed it was before. Keep in mind that the engine was off at this point.