Be a Clever Customer when buying a used car - do a car recall check, it's fast and free. Many used cars have open safety recalls on them. Dealers may not be aware or may not take the initiative to get the recall repair performed before the car is purchased. Once you purchase the car, it is completely your responsibility to find out if recalls exist for your car and get them repaired. Know before you buy, and get the repair done first, or get the dealer to agree in writing to perform the repair.
If you're shopping for a used car and have your choice narrowed down to a couple of options, or you think you know what kind of car you'll be looking for, look up the recalls and crash ratings here. It might help you make a better decision.
If you're seriously looking at buying a specific used car, you can check out the recalls and crash ratings here by entering the Vehicle Identification Number or VIN. You'll also get detailed specs for that specific vehicle.