From what I understand from owning two 850's (boring but reliable N/A 850s) and reading a lot of stuff on them is that entire interior is going to rattle over bumps no matter what, there's a high probability that your ABS computer is shot (they rarely lasted more than a few years), the window switch needs to be cleaned or replaced (a common problem), and you might need a new 02 sensor. My blower also recently stopped working on all speeds but 4. Some helpful advice from Klaus and others on this board had me replace the resistor pack behind the glove box. If it doesn't work in speed 4 it might be something else.

There's a guy who rebuilds ABS units for a pretty reasonable price. You should be able to find out his name by searching this forum.

Anyway, that's my $0.2. There are much more knowledgable people on this board than me.