There's a Chinese idiom that says, "一波未平，一波又起" (one wave has not yet subsided, another wave has started), which can be used to describe my situation today.
I got my car back from AAMCO today. Transmission overhaul, and three of the four engine mounts were replaced (one was replaced shortly after my accident, so I assume that's the one that's still holding up). I'm supposed to bring it back in about 10 days for a final check, to make sure that everything is in proper working order.
After driving a Dodge Neon for a week, the difference is definitely noticeable--the ride is smoother, and quieter, the steering wheel is lighter, and it is more comfortable overall. Virtually all of the problems I've been noticing with the car before taking the car in are now gone.
However, in just going from AAMCO to my workplace, with a distance of only a mile, I noticed something very disturbing--the engine temperature, or at least, what's showing on the temperature gauge. As I approached my office, the temperature crept up to near the redline.
During my lunch break, I stopped by Autozone and picked up a bottle of Redline Water Wetter, but the coolant reservoir in my car was extremely full, so I was not able to use any of it. I guess AAMCO probably added some coolant, which changed the mix ratio, and resulted in what I'm currently seeing. At least, I hope that's what happened. The alternative is either that my thermostat is broken, or that my radiator is shot again, and I've got to replace more stuff.