Answer:
You can either sell them for a relatively small amount of money or you can scrap them. Or, if you really like your rusty car, you can spend a bit of money on 'doing it up'. By this I mean giving it a paint job and taking real good care of it and fixing everything that needs fixing. It also depends on what car it is. If it is vinatge, 'do it up'. If it isn't, sell or scrap.