In the end your best bet is to not trust any one source, but to take a look at everything. There are many reported cases where CarFax not only missed accidents, but actually recorded accidents when there were none. Personally I won't give CarFax another dime of my money because THEY ARE AN INTENTIONALLY FRAUDULENT COMPANY. But that doesn't mean AutoCheck is the complete answer either. Order up the AutoCheck as a first line of defense when researching a vehicle, but then be sure to do a detailed inspection yourself with our checklist, or if the seller will allow it, have it looked over by a qualified shop. Even better, have a dealership like CarMax take a look. Their buyers go through a year's worth of training to learn how to spot damaged vehicles by details as small rough spots in the paint on door jams or slightly mis-aligned interior panels.