No substance. How could the government limit the size of vehicles? > Companies will never voluntarily reduce their SUV sizes unless outside forces pressures them to do (like $10 oil). If oil (say, brent crude) goes to $10, something has gone very awry.
> How could the government limit the size of vehicles? Tons of ways. For instance, "a car must get at least 40 MPG". "A car can weigh no more than X". There are lots of whats to phrase the rules. Or do you mean "how could the government possibly enforce a law against a product in a highly regulated industry with compulsory registration", in which case it seems obvious.
It complains about environmental matters, and then it goes on to complain about weight. Make one wonder if the author has ever weighed a car-sized battery.