I have an '01 Pathy and live near Toronto, Ontario. In the beginning of '05 I was looking at '01 to '03 Pathy's, and every single one of them had rust coming from the back window trim at the bottom. The '03's just had less of it, the '01's had more, but they all had it. I bought an '01 that had the trim rust on both sides, and a wiper arm. That's just how they are. But there's absolutely no rust on the body anywhere, or on any Pathy I've seen of those years, come to think of it.
If you're picky, you can buy new wiper arms and and replace the window trim, but it will rust again eventually, especially with our winter climate & salted roads...
Joe.