An ominous brown stain on the fender. A bubble in the paint at the bottom of a door. Soaked floors after hitting a puddle. These are signs the iron worm has been hard at work: rust.

Otherwise fine cars are routinely sent to early graves because the become rusty cars, even though it’s a largely avoidable problem. With iron-based metals, battling oxidation can feel like a Sisyphean task. In spite of the advanced coatings and alloys developed by chemists and engineers, iron’s unstable chemical makeup means it will always succumb to rust in a natural environment. In fact, iron and most steel will completely reduce to iron oxide and other constituent elements over a long enough time.

This doesn’t mean that your car is doomed! Understanding how cars become rusty, your car’s problem areas, and how car rust can be repaired from that brown, flaky trouble means that your pride and joy can stay on the road as long as you do.