Die, agnostic!
So I brought my car into the nearest Firestone to have the oil changed and have it looked over for the winter. There had been a couple times when the engine choked right after ignition, and I figured that whatever had caused that would be caught when it was checked out.
The mechanic called me a few hours after I dropped it off, telling me that it was in a horrible condition. It had stalled out five times when he went to bring it into the garage, and once they opened it up there was some kind of fluid leak. Needless to say, this was a surprise- it's never stalled on me before, and though I have noticed a drop or two of oil(?), I never thought it was that big a deal- it is eight years old, after all.
When pressed about the exact cause for the problems, he couldn't say- but did recommend an engine diagnostic test, as soon as his technician arrived the next day. So, I resigned myself to being without a ride for a day, and waited for the call. Eventually, it came- the verdict delivered by the $80 diagnostic test was, "your car is in terrible shape, but it doesn't know why."
Money well spent.
The mechanic did have some suggestions: the air filter was dirty, the ignition wires were old, the fuel filter had never been changed, the oil pan gasket was leaky, the brake fluid was old and gummy, the tires were out of alignment...
"Look," I said, "change the fuel filter, fix the oil pan, and flush the brake fluid. The tires are obviously not part of the problem, and the other two I can do myself." Fair enough, right? Even if none of those directly caused the 'problem,' at the very least they're good preventative maintenance, and I haven't put dollar one into this car's upkeep so far, so I'll swallow it. Turns out the whole tab (oil change and winterization included) was $300, and the extra stuff I wouldn't let them do would have cost me another $300. Which I could spend $50 of parts and less than an hour to do myself.
Hey, I didn't buy a Haynes manual for nothing.