A carbon tax would not eliminate all petrol cars tomorrow, would it? It would increase the price of fuel, which would encourage some to make their next vehicle an EV in place of ICE. It would inevitably encourage cities and petrol stations to add EV infrastructure too.
Not entirely sure how the US taxes vehicles, but personally I would put some combination of fuel (carbon) tax, increasing monthly well in excess of inflation and a vehicle tax that cost some combination of vehicle weight and emissions. The combination effect of which would be to discourage ICE, pickups and 4x4s whilst encouraging smaller EVs.