So I was recently shopping for a used car and figured, okay, lots of ads and buying guides and even some reputable organizations highly recommend a CARFAX check. And even though I knew I was buying a beater (bought it as a spare to teach myself stick shift on), I figure... sure, may as well use it to separate wheat from chaff.
CARFAX is arranged with a silly (from the customer's perspective) sales model. You can pay $15 for ONE VIN report, or $25 for a month of unlimited VIN reports.
Well, duh.
So I got the month, and it didn't take me long to find a car and buy it. But now I've got all this CARFAX subscription I'm not using. So I started running some other cars--my own, friends, etc. Because it's fun.
And found that... really, you can't put a heck of a lot of stock in CARFAX's clean bills of health.
One car I ran came back with "no accidents reported" when in fact it was in two police-reported fender benders and another insurance incident.
Another car that I ran that had suffered thousands of dollars in flood damage came back with--ta da!--no flood damage reported!
So the data, or more specifically LACK of data, you get from CARFAX can't be taken all that seriously.
Sadly, it's still worth the $25, just to weed out any serious heaps from your search. But if it comes back clean... your work has really only just started.