Do you honestly believe that given enough money politicians can come up with a viable solution for climate change? Mind you those are the same people who want to end privacy on the Internet[1].
Same people who came up with European Union’s biofuel mandate which caused deforestation of Indonesia for palm-oil plantations. Across the pond, it's the same people that subsidized ethanol fuel which, more or less, benefited only corn farmers.
It doesn't really matter. Even if the tax revenue was piled up and set on fire, the planet would still be better off for it
For example, in EU car manufacturers have to keep average CO2 emissions of new car sales below 95 g/km. VW buys a large amount (I believe it was around 37%) of their ID.3 electric car to reduce the average emissions of their newly sold cars.
So what you suggest is we take money from poor people and burn it. I fail to see how that will help.
By "at source", I mean that car makers should not be taxed.
Instead, fossil fuels should be taxed as close as possible to when they are pulled from the ground. Not when they are used (like a car does).
Then if car makers decide to build big diesel chugging vehicles, of course their market will be severely limited because not many people will want to pay the cost of running them.
Car makers are therefore still incentivized by market forces. to build efficient vehicles, but we don't need artificial and easily gamed regimes about what proportion of their production is fuel efficient.