Locking a dog in a car is not cruel per se
Of course it can be cruel, anything can be made cruel and that is where the law is required, but if the dog in the car is not suffering, then it is not cruel and the dog is probably just having a great day out.
Just because there are idiots in the world, does not mean that everyone in the world has to be treated as if he is an idiot.
The law is fine as it is.
please read up what can happen to dogs locked in cars i ve witness this happen its very distressing organ shut down brain begins to boil convulsions to the point were they can bite off their tongues literally start to cook inside this happens within minutes