The media is one of the most powerfull tools to subdue people's mind to believe something is good bombarding our eyes thousands of times with their ads on TV,radio and news papers,your mind becomes actually "programmed" to listen to those ads and believe that those are good and trusthworthy.

But if you rethink about this situation with such companies as carfax or autocheck you got to understand that they job rely on the info that is provided to them from different sources such as DMV,bodyshops,autoinsurance,etc.

That's why you can't rely on or trust these companies because they cannot provide you with all and/or the right info to decide if the car you are looking into is the right one.