I'll give the counter argument to Henry fl. It's been a really long time since I've seen cars rust through. Recall the 90's Ford windstars that all rusted their side panels and doors? If the car is kept clean and waxed once in awhile you should be just fine, unless you are looking to keep this as a show car. I've driven all of my vehicles way past their normal life (some 20+ years) and rust is definitely not as bad as it used to be in the 70s
I had a 2001 Cavalier rust through, and that's what ultimately got me into my Volt. Of course, it too almost 16 years and 200,000+ miles to do it. . .
A little care goes a long way.