Got a situation with a '99 Mazda Protege 320k miles that keeps rusting out the radiator. Local shop says that water must've got into the engine at some point and that rust in the engine will keep spreading into the radiator. No way to remedy it. Their recommendation is to put a new engine in it if I want to keep it on the road. Does that sound right? Any incite to offer? As it is I'm adding about 2 cups of fluid each morning I need to drive. Not in a position to consider replacing the car...engine swap even would be really hard.