Real-estate is already taxed in most places in America. Most European countries also tax cars based on their engine's size.
Same as before:tax authorities do NOT tax the car. they tax the buyer on the transaction, and there's some form of "possession tax". that's not a tax on assets. If it were a tax on the car, a car owned for example by a deceased penniless owner would still pay tax, and above all, it would be economically capable of paying such tax. but it does not: even taxes related on car possession tax the owner, not a car.
Bear in mind that these kind of stamp duties bear no relation of the use of public resources that using a car entails: If I want to tax for that, I'd tax the fuels, and that's exactly what governments do. when they do anything else, like "taxing cars based on engine size", they are simply meddling in people choices unrelated to use of resources and so on. I think that it's "politically convenient" to set up a labor intensive organization to collect and check a taxation which could and is more efficiently collected in another way, and above all it is unrelated to usage, income of the owner, efficiency gains and so on.