From tomorrow (1 October 2015) it will be illegal to smoke in a car (or other vehicles) with anyone under 18 present. The law is changing to protect children and young people from the dangers of secondhand smoke.
Both the driver and the smoker could be fined £50. The law applies to every driver in England and Wales, including those aged 17 and those with a provisional driving licence. The law does not apply if the driver is 17 years old and is on their own in the car.
The law applies to any private vehicle that is enclosed wholly or partly by a roof. It still applies if people have the windows or sunroof open, have the air conditioning on, or if they sit in the open doorway of the vehicle. The law won’t apply to a convertible car with the roof completely down.
For more information, see the guidance on new rules about tobacco, e-cigarettes and smoking
Source- Department of health