Is it actually possible to have the knob carried out? e.g. from the TÜV. I have been driving without the knob on the steering wheel for 10 years now. Was also never a problem. Only recently I had a small accident and the policeman was unfortunately very attentive and has choked me a procedure for driving without driving permission, because just said knob was not on the steering wheel. And now I want to have this thing legally away.