What is a "rust-through warranty"?

What is a "rust-through warranty"?

James Bell (Publisher, Auto Reviewer) gives expert video advice on: Does every new car come with a warranty?; What should I look for when comparing a new car warranty? and more...

When understanding car warranties, a rust-through warranty is something that really came about in the 1970's when vehicles were built to a much lower quality standard, where in very wet or salty air conditions rust became a big problem. Technology has moved forwards somewhat and that isn't as much of a problem as it was then. However, a rust-through warranty is still an implied warranty that comes on just about every vehicle, such that you do not need to be concerned that no matter where you live in the country, rust will not eventually eat away the skin of the vehicle.