"Je mag niet met de auto rijden."
Translation:You may not drive.
Exactly. Wouldn't you translate "You may not drive" as "Je mag niet rijden" as you might not be driving a car, it could be a lorry or motorcycle.
I suppose there is a slight problem as "Je mag niet rijden" could translate as "You may not ride [a horse]", so using "drive" shows that we have spotted that is a car.
But I don't think it is wrong in English to put all the information about what you are driving.
I think there is a nuance here. Permitted is more having someone allow you to. Can can mean either ability or permission. So, I know you can drive (ability) but you can't drive my car(permission). I still haven't quite figured out how much mag (moegen) covers)