It's the same thing really though. If you don't charge someone a load of tax they would have otherwise paid, it's really a subsidy in a different name. People

It's the same thing really though. If you don't charge someone a load of tax they would have otherwise paid, it's really a subsidy in a different name. People would still have to buy cars. They would have paid the registration levy and VAT, now they don't need to. The end result for the treasury is the same whether they didn't get it in at all in the first place (tax relief) or paid it out instead (subisidy).