what they should do really is limit the brake horsepower of a car for the first year (eg 90bhp, as that then allows drivers to have anything up to around a 1.4), then after a year of driving, they can have a car up to 120 brake, and then after that no limit. That would be suitable. As its the same/similar with bikes. At 16 you can have a 50cc restricted to 30 (yet non are as its dangerously slow), then after a year of motorcycle experience/or get a car license, you can have a 125 upto 14 horsepower (not sure on exact bhp limits mind you).