Depends. If you buy an actual old clunker or a decent mileage, solid car - this makes a huge difference. If you knew how little maintenance I have to put on all three "old" cars I have you'd be amazed. Oil changes, fluid checks, brakes and the occasional tune up although that's rare nowadays with all the cars being EFI.
Even my 18yr old Sidekick all I do is change the oil 2x year, look at the spark-plugs once in a while, check fluids at least once a week - takes 10 minutes to do all 3 cars...
You just need a keen ear for any abnormal noises, whistles and rattles. Anything out of the ordinary needs to be identified and immediately addressed. Pulleys, belts, filters, brake usage warning brackets, etc.
Transmission on my model is 5sp auto with shiftronic. Also my tyre size is 205/55 R16. I picked up the 18" R-type Pegasus imitation wheels last fall, not sure if I'll install them with summers in April, I still feel 18" to be too low for Quebec roads. They might wind up on Kijiji or the Volvo forum.
They are gorgeous but we are in Quebec... if we were in South Carolina I wouldn't even think about it twice.
You daily drive you Sidekick? If you put 15-25k per year on it with only oil changes, color me impressed.
In my mind, a 30 year old daily driven sidekick would need pretty serious maintenance, and rust repair/full respray every 3-4 years. Our winter can be pretty rough on those old Suzukis.