I'd also try to find a forum for your car. For instance, I know that on my Focus, wheel bearings are a weak point, a bad sensor on the firewall (can't remember what its called) can cause a poor idle / dying at stop lights, and I can completely renew my suspension to SVT Focus specs for under $300, among many other things. For my diesel truck, I know that a "bad transmission" can be nothing more than dirty connections on the battery, the transmission bands need tightened frequently but not overtightened, and the cheap lift pump, if it goes out, can kill your expensive injection pump, so it pays to monitor the fuel pressure with gauges. Etc etc. No (ok, most) mechanics would ever tell you that kind of stuff.
But some people are just not car maintenance people. Like I use computers every day of my life but if I get a black / blue start up screen or freeze up, it goes to a repair shop I trust. Even if its as simple as doing something with the harddrive and reloading software. Not something I care to learn.