Can I get some used car buying advice?

[LeftyMom]

My mom has just about the worst luck in the universe with cars. She's foever getting a lemon, getting screwed over, etc. Anyhow she's about to get some of her retirement money from work and needs to get something reliable that will last a while, used and not any more money than needed. I have no real trouble with my car (I have a Saturn SW1) and have encouraged her to look into that or the more ubuquitous sedan equivalent, but if anybody else can suggest something to keep our eyes out for, I'd appreciate it. She's looking for reliablity, it needs so be something with a real backseat rather than a pickup or coupe, she'd prefer it be somewhat economical in terms of repairs and gas and since she's got significant health issues already and she transports my kid sometimes, I want to be sure it's something safe.

Any thoughts?