Only I think the tax should be indexed, and increase semi-exponentially based on the price of your vehicle.
That would satisfy both sides of the argument. The wealthy would pay WAY more for their ego-mobiles. The poor and middle class would be paying next to nothing for their Honda Civics. And all the money collected would be made available to improve public transit.
Guess what, you live in a large, crappy place in the worst parts of the Bronx, you pay less than the guy who lives in the tiny apartment in the luxury building in Manhattan. The small apartment likely even uses, less water, less power, less heat, and fewer city services like police and fire.
But so what?
You know why we do it that way? Because it only makes sense to do it that way.
Sorry, but of course it should be based on price. All things of this sort are.
Just pass the tax in it's simplest form and then see if further adjustment is needed, the perfect being the enemy of the good and what not.
Getting 'right of way', building permits, hiring firms, planning massive construction projects involving 'new technology' etc. etc - this is 'complicated' beyond the threshold that I would trust the NYC government.
But some kind of tax on cars is within feasibility.
I mean really, what's to argue? You could argue whether there should be a tax at all I suppose. But not much else.