I would think the tax on the value of the car would be better handled by taxing gas much more heavily. It seems to me that all of the very expensive cars have terrible mileage. If we had a good carbon tax, it should do a good job of taxing what we really want to be taxed, which happens to coincide well with luxury vehicles.
As has been discussed ad nauseum elsewhere, electric vehicles aren't appreciably more heavy than other commuter vehicles, especially given that damage to roads is non-linear. And as for them not using gas -- that's why taxing carbon would handle it. If electricity comes from natural gas or coal, then you pay tax on the electricity accordingly.
