ac password or switch

[djindore]

Dear sir
I have a fleet of 5 taxis. My issue is that the drivers misuse the air conditions specifically they run the ac on the highest when it is not hot just out of fun. Can i use a password to switch on off ac or a lock to enable disable it which will help save petrol also hence higher profits. I think it is long due in ac innovation that a password or lock should be available to switch on/off ac in cars. Wonder why big car makers didnt install this by default in cars.