So far as I can see, the new law does not protect under 18's from first or second hand smoke if the under 18 is the smoker and is on his/her own in the car. But what if the 17 yr old smoker was not smoking at the time an over 18 was smoking in the car, could the law be used to prosecute the over 18 for smoking in a car with an under 18 present???

As is common with the present government the law is extremely badly written.

A literal reading of it means that if a 17 year old is driving a car by themselves then they can smoke.

If their 60-a-day dad gets in the car for a lift then neither of them can smoke.

If the 17 year old lit up with his dad in the car they could then be fined for endangering their own health.

Plus, as the police have a duty to confiscate any smoking paraphernalia from under 18s they catch in the act, the 17-year-old will be pretty cheesed off. As will his dad if he is seen buying baccy for him...