would anyone say to not buy a cinq with rust on it im looking at one with abit on one of the front archs if thats starting to rust is the rest of the car more likely to rust then one with no rust?
It might have had replacements, however bear in mind that the youngest Cinq is now pushing 11 years old, and galvanising will be attacked by stones etc over the years.
Wings are dead cheap, but do have a close look in the rear corners behind the wheel arch. That will tell you whether the rot has really set in.