> Ultimately the regulation achieves its goal, reducing CO2.

Does it though?

Instead of Fiat reducing their product's CO2 emissions, isn't it actually the case that they've just done some fancy accounting and now say their emissions are lower because the paperwork now says Tesla is part of their fleet?

Tesla were going to make those cars anyway, so really Tesla gain the free money from Fiat, and Fiat keeps making polluting cars, and we all get to suffer the consequences of no actual reduction of CO2 because ultimately nothing has changed apart from some paperwork that follows the letter of the law rather than the spirit?

Doesn't seem that great to me.