You have indicated that this is the final series of Saab 9-5 which, of course, is an extremely rare car because it was only built for a year before SAAB went bust and for that reason will eventually gain classic status.

The many changes of owner were probably due to the uncertainty about the future of SAAB. But if you can find a reasonably local and keen Saab specialist it could be worth a punt, even though body parts are likely to become difficult to obtain. If it's merely a late registered old model 9-5 then, unless it's cheap, I wouldn't bother and if it's a diesel leave it well alone.