CarFax unlimited reports option is a great value when shopping for a used car. As we purchased our last vehicle, I kept one browser window open on my favorite used car search site and another on CarFax. Copying VINs of interesting cars from one window to the CarFax window helped me very quickly rule out vehicles I didn't want (reported damage, salvage titles, cars from "salt states", etc.) That said, CarFax cannot and does not show everything; accident damage and repair doesn't show up if the owner fixed it or paid out of pocket without involving insurance or police. It's still "buyer beware" but CarFax makes it much easier to be an informed consumer.