The national bank could print money and use that to buy the car but these days financial transactions are carried out electronically so there is no need to actually print the money Instead a number on the national banks computer system is added to Its just another way of printing money but electronically Of course the more money you print the less it becomes worth Look what happened in Zimbabwe printing millions of billion dollar notes didnt mean everyone was rich it just mean that a billion dollars could buy you less ie inflation occurred by deflating or diluting the value of money