If you experience the same issues I had, (computer more than powerful enough but physics bar maxing out) delete the shaders. It cleared my issue right up.
Spent most of last Thursday night and most of Friday talking to people here about it. Went and cleared the shaders and it worked fine afterwards. Thought it was odd as when I made that video it suddenly started happening. But then, I had been changing graphics settings a lot and using new tracks and mods.
Messing around in the F2. Driving in reverse and other plain stuff. Honda BTCC on medium tires Radical practice @ AMP