We're right on the borderline here, so there are both nice clean cars and ones that looks as if they've spent their entire lives in Boston or upstate NY to be had. Also, there are a lot of people who move here from somewhere else, and bring their unrusted southern cars with them. (my 740 spent at least some of its early years in Greece, of all places, and an Alfa Spider I once owned had been in Spain for a while---both nice dry climates)

In any case, thorough inspection of the underside of any prospective purchase is required.