The law on e-cigarettes and smoking in cars has changed since October 1st 2015, which means you have to be over 18 to buy e-liquids and it will be illegal to smoke in cars if there is someone under 18 present.
You Have To Be Over 18 To Buy E-liquids
From October 1 2015, it will be illegal for retailers to sell e-cigarette devices to under 18s for the first time and you will also have to be over 18 to buy e-liquids.
Retailers selling eliquids and ecigarettes to minors will face fines.
In vehicles, drivers will face a fixed penalty of £50 if they permit someone to smoke cigarettes in the car if there is someone under 18 present.
If this law is broken Enforcement officers will decide whether to issue a fixed penalty of £50, or the offence will be referred to court.source