Another way of looking at it Martinod is that it would be good for people wealthy enough to buy a new car but bad for the poorer people who would have to pay for it through taxation.
Or you could look at it another way…the government takes the VAT off…encourages more people to buy them…the car companies are happy as they are increasing sales and they can make more cars…making more cars means they can produce them for less money so they can produce cheaper cars which encourages more people to buy them.