I don't know how you get downvoted on this. From my point of view you proposition is very rational.

Most of the industrial developments happen incrementally not overnight. Gradually setting the right incentives so consumers and suppliers find a satisfactory solution seems like the best outcome for everyone. I don't think any politician has a crystal ball to predict the future, the law seems to be just a populist proposal to gain votes.

Plus cars are not the only source of CO2 emissions.