I would agree with Neil that this is made out of "cheap" stainless steel. However, if you live in southern climates of the US, the corrosion issue is probably not a big deal. This system would probably hold up just fine if it is never exposed to road salt and brine. It's the only one available to my knowledge, which means the only other option would be to get one custom made, which is much more expensive.
The 2000 V70R had a nice dual exhaust system from the factory, but it is unfortunately NLA.