Of course. repairing rust is worth it for an old car. Rust is one of the most insidious enemies of a car. It starts out small, as a tiny spot or two, but given time and moisture it can spread quickly and do serious damage. Many people think that repairing rust is simply a matter of slathering on some paint, but unfortunately, it’s not that simple. Once rust has taken hold, the only way to properly repair it is to remove all of the affected metal, treat the area with a rust converter (which helps to prevent new rust from forming), and then shore up the area with new metal.