Are NOT necessarily reliable. We recently sold my wife's car to Carmax. Carmax pulled the report on it and it came back clean. My wife's car had been in three wrecks, two of which were $5000+ in damages. All three collision repairs were done at a Ford dealer. Yet, the Carfax report showed no history of collision or damage. We honestly answered the questions about prior collisions, but my guess is that if Carmax turns around and lists her vehicle for sale, a prospective buyers will pull the Carfax and find a clean report.
In shopping for her replacement car, we found that vehicles with all the maintenance records on the Carfax were generally the ones that qualified for certified pre-owned. I'm sure there are many good reliable clean history cars out there that are not certified pre-owned but just be aware that a clean Carfax report isn't a guarantee that the car hasn't been hit or damaged in the past.
In shopping for her replacement car, we found that vehicles with all the maintenance records on the Carfax were generally the ones that qualified for certified pre-owned. I'm sure there are many good reliable clean history cars out there that are not certified pre-owned but just be aware that a clean Carfax report isn't a guarantee that the car hasn't been hit or damaged in the past.