And the average age of a car on the road is 11.9 years, so all new cars are zero emission by 2035 and nearly half of the cars on the road are zero emission by 2045 when energy generation is 100% clean.
This sounds like exactly the right plan, get one of the biggest and most distributed users of dirty sources to electric, then worry about converting the highly concentrated (relative to cars) power producers to go to 100% clean energy.
I'm not sure how your measuring "dirty" but in many places, its the electric cars which are "dirty". Modern gas/petrol car's exhaust is only really adding CO2+H2O to the intake air. When you look at things like
(which is slightly dated, but only a small portion of the coal has been replaced with NG, and the wind+solar is negligible) its not really a pretty picture.
So, yes, once all the power sources are C02 free, or at least lower than traditional petol, its a net win, but its a mistake to think that moving to electric cars by itself is anykind of win. Particularly, in the current climate where your just moving to NG for the majority of the additional load despite the claims of wind/etc.
Put another way, for every KW of wind/solar being installed your also getting a KW of NG. So best case if you live in a nuke/hydro/coal free area, your shifting to ~30% NG. Which isn't any way to solve the climate problem, its a feel good measure for ignorant people.
This sounds like exactly the right plan, get one of the biggest and most distributed users of dirty sources to electric, then worry about converting the highly concentrated (relative to cars) power producers to go to 100% clean energy.