Individuals – This is usually the best way to find a good car at a good price. You may want to pick up an old newspaper to start, as buyers who have gone a few weeks without selling may be more likely to come down on price.
New Car Lots – These can be good places to find a used car if you’re willing to haggle. Of course, dealers will price cars higher than blue book value, but they may be willing to come down when sales are slow. Don't be afraid to make an offer you think they won't accept, because you have nothing to lose.
Some dealerships offer certified used cars, which means that the manufacturer (and check the paperwork to make sure it’s the manufacturer and not the dealership) covers those cars under warranty. That means that you won’t have to do any further checking to make sure the car you want to buy is in good mechanical condition. It also means that you’ll pay an extra $500-$1000 for that privilege.
Mechanics – Your mechanic may know of customers who have cars for sale, and of course, he or she will probably have a good idea of the kind of condition a customer’s car is in.
Used Car Lots – I don’t recommend buying from used car lots. Their prices are inflated, and they tend to be here-today, gone-tomorrow sort of businesses. If you come across one with a good reputation, it may be worth investigating.