I think it's much better to tax the cars you don't want rather than to subsidize the cars you do want. Why? Because the state is not doing well financially, and they are not in the place to drop 3 billion on subsidies.

I think it also makes more sense from a moral standpoint. If using a gasoline powered car contributes more to the environment's woes, paying the tax is giving back to society in return for having made it a slightly worse place via pollution. It is also better to directly tax the undesirable car that way the tax is directly associated with the undesirable car, as opposed to a general income tax. This may be less politically feasible for that reason though.