Gear-obsessed editors choose every product we review. We may earn commission if you buy from a link. Why Trust Us? An ominous brown stain on the fender. A bubble in the paint at the bottom of a door.

There it is creeping in quietly through the cracks and onto exposed metal. And like bad acne on a teenager, the scars of rust are permanent. But could you have prevented it? Maybe. Maybe not. But ...