You absolutely are not allowed to take your motability car around the Nurburgring if you crash or someone crashes into you you will have to pay from your own pocket also if you damage the barrier you need to pay for that and also if any oil or brake fluid leaks from your car and an expensive car up to a million pounds crashed due fluids leaking from your car I would strongly advise against it on that basis
on another level you will be endangering every motability customers due to any bad publicity you may get yourself involved in
so do your research and think it through carefully it’s not called the green hell for nothing