I have a few methods that I know of that are very effective in finding a car and not paying a ton of money. You will need to be patient in your quest in order to be successful. The car you want at the price you want will be available if only you'll agree not to be in a rush. Getting into a big hurry may mean that you select a car that will be more of a headache than it's worth.
1. Getting a second hand car through dealer leasing
This is something that is growing in popularity, as people are trying to get better second-hand cars, but need to save money too. Using the dealerships' finance options will help in keeping your monthly payments low. However, make sure that you check on the insurance costs and interest rates. The dealers might try and rip you off by charging a lot of interest, but it's something that can be overcome if you visit enough places. Plenty of folks choose to go this route to get a nicer car for less money than buying brand new.
2. Buying rebuilt titles
There can be a serious amount of damage done to a car with a rebuilt title, so be sure to check it out carefully. It was destroyed once, and rebuilt to work again. Be very careful with the cars that you choose via this method. Folks who have a trusted and reliable mechanic can ask them to go along and check the car out on their behalf. Since cars with rebuilt titles are such a risk, you'll be able to get a good deal provided you choose carefully. just be sure to verify that all is in working order with the vehicle and you'll be fine. Just because it's rebuilt doesn't mean it has to look or drive terribly. The properly rebuilt car should be virtually indistinguishable from any other car.
3. Government and Police auction purchases
Every time a car is repossessed or sent to an impound, the bank / government generally sell the cars through auctions. Most folks at these auctions are from dealerships and are looking to find something nice to buy cheap and then flip for a profit on their lot. The average person can gain access to these auctions if you know what to look for, and there are many different ways for you to do that. Check online, check the yellow pages, and even call around. There are people who know when they happen (a few each month at minimum,) and you can get some killer deals there (anywhere from 10% to 30% off on average). Don't get scammed by people promising 90% off, that is RARE.