We have already established However, many of us use them as a first line of defense against cars that have been damaged or totaled. But what happens when CarFax doesn't report the information in time? One couple found out the hard way.

According to Miami news affiliatethe Watsons purchased a pre-owned Corolla in 2011. They did the smart thing and checked the CarFax. According to the report at the time, the history was clean, so they purchased the car. A few years later they decided they needed a bigger vehicle for their family and attempted to trade their Corolla in for an SUV.

The dealership initially offered them a price of $3,500, but after running the VIN through the CarFax database, they found that the car was declared a "total loss" in 2007 by an insurance company. The dealer then tells the Watsons that they will not take their trade, due to the "totaled" status of the car.

CarFax claims that their "data source" was not reporting this information until 2013 and that this particular car would not qualify for their "buy back guarantee" due to the fact that CarFax did not delay the report.

Consumer protection attorney Dana Manner says that the variety of data sources that CarFax utilizes are not always accurate and timely with their information. He recommends starting with a simple Google search of a vehicle's VIN to see if any accident pictures show up. Manner also strongly suggests having any pre-owned vehicle inspected by a trusted mechanic to reveal any damaged that was repaired.