These are rules addressing properties inside perimeter of diplom

compound. It does not say anything about how such a vehicle outside diplomatic perimeter follow the laws of the country they reside. I believe that they must follow the laws of the country in which they reside. In any dispute, they have diplomatic immunity. That has to be decided AFTER involing parties have been IDENTIFIED to be diplomats. Charges against them would be dealt differently

Diplomat CAN ONLY BE IDENTIFIED by photo diplomatic identification passport

This dispute in particular has not reached to this point simply because person in car refuse to identitfy himself. Probably because he think licence plate on car can be used as ID. Well he is wrong

If diplomatic car was stolen by thief who drive illegally or committ crime, will police stop him on road because of an mark on the car? Think about it. Try to imagine such an event in downtown of Beijing.