An update on the car situation:

Late last week the engine started misfiring, so I made an appointment
to take it in today. One cylinder was having problems even when its
spark plug was swapped with a good cylinder’s, which meant replacing
the ignition cassette, which is what a Saab uses instead of a coil
and distributor — it’s essentially one ignition coil per cylinder,
plus timing sensors and so forth. Wasn’t a cheap repair but I saw
it coming.

The good news is that it resolved a lot of problems which I thought
were just the miles adding up — some sluggishness and roughness
accelerating and decelerating are gone, and some of the vibration is
gone too, so it sounds as though I’ve had a timing problem for a
while.

It’s one more breath of life into the thing, at least, so I think
I’m going to stick with it for the time being.