Have a look at the thread above named:

In need of a manual...any suggestions? [S70]

for sites with service info. It has the Bay13 reference (a
site that should be in the volvo owners manual).

I have a 98 and have had a few of the same problems. But
I have had few problems in the last 2 to 3 years. The first
18 months I had quite a few and those were fixed under warranty.
You car should be in middle age and the 98's do ok in "middle age".

I'd try cleaning the window switch with lighter fluid. We used to
use that to clean up interior parts when I had a job installing
car stereo systems (in college). Test first to make sure it
does not stain.

My power antenna frequently sticks going up the first time. I
turn off the radio and try again. It always works the second
time. I;d avoid oiling the mast since oil attracts dirt and makes
it worse over time. Clean it instead. Note that WD40 is a solvent
and is good for cleaning if you spray some on a rag and wipe down
the antenna.

Finally, the car does have squeeks and rattles (although not as bas
as my wifes 1995 855). I just turn up the stereo (and avoid 50
series hi-prformance tires which make it worse).