I hate it when my car needs work - we've usually moved to a new place, where I don't have a trustworthy mechanic, and I don't understand cars well enough to know if the repair shop is being honest. For that reason, Lindsey Knerl's article at The Dealista is really interesting to me: How To Save Money On Car Repairs. Be warned, the second paragraph is an advertisement. I don't know why they couldn't put in a different font, or italicize it, or something, but I was quite confused the first time I read through. Once you get past the ad, there are a variety of ways to keep repair costs low and make sure that you are fixing the parts that are broken.
Considering that your car is usually either your biggest or second biggest expense, these tips could help you save a lot.