The
'Good as New' Used Car Buying Guide' also says to buy from dealers and haggle a lot. He has strategies for getting servicable non-thrashed vehicles for under $6000 (as low as $3000 I recall). He says stay away from the rental cars.
FWIW it's worth, I got my last used car from a private seller - a clean 96 Acura Integra with about 59K on it for about $8000. Worked out allright but I don't find buying used cars particularly fun.
