eex2 ... what I think you are asking, is "are the exhaust systems on North American Foresters made from stainless steel?. And if so, why is mine (in the European market) so rusty? Is mine also made of stainless steel?"
Yes, they are made from stainless steel (here anyway, and likely in your market), but keep in mind that all grades of stainless steel are not impervious to rust. The most common grade of stainless used in automotive exhaust systems does show corrosion effects over time, but it does so at a much slower rate than common mild steel. I think (but can't say with 100% certainty - it has been a long time since my material science college course days!) that this is called grade 409 stainless steel.
If, however, you buy an exhaust system that uses grade 304 stainless (also called 18-8 ss), it will start out much shinier than a 409 system, and stay that way longer. But, 304 is harder to work with, and the base material costs more, so OEM's tend not to use it.
All that said, the exhaust on my 2010 Foz is also showing signs of corrosion. I bought it ~ 2 weeks ago, but it did sit at least part of this winter at a dealer in the Detroit, Michigan area, and possibly got a little 'test drive' use while there. The amount of corrosion that I see is what I'd expect after some exposure to the road salt used here in winter.
Stainless steel - Wikipedia, the free encyclopedia