I think that I have just figured out that 'rust free' has several meanings':
1) There will be no charge for the rust.
2) There is no rust that you can see from a picture
3) There are no large holes in the car from rust It's kind of a Democrat thing; if it doesn't fly up and hit you in the face, it's not there!!! I just looked at a car with heavy flaky rust covering the trunk and the floors of the car. Seller advertised it as 'rust free'?????? CAVEAT EMPTOR