Used Cars: Prior rental agency cars, rental car agency, rental car companies

Question
I'm looking to buy a 2006 Chevy Monte Carlo LT.  Reading the Carfax reports on 2 cars I've been looking at, I noticed that they were previously owned by a major car rental agency.  Both were then sold at an auto auction.  One had less than 16,000 miles when it went to auction.  This sends up a red flag to me.  Why would anyone sell a car with less than 16K miles on it?  I suspect that both have been in accidents and repaired, and the rental agencies no longer wanted to deal with the cars.  Do you think I should worry about buying a used car that had been in a car rental fleet, even though it is now a "GM Certified Used" vehicle?

Answer
In my opinion the decision why a rental car agency sells a car is made on up the chain of command as opposed to the actual facility where the car may be.  With that being said I would still check all the things available to you. For instance definetly run a carfax report, but if it is GM Certified Used, you probably dont have much risk of anything major being wrong with the car.  What I would do is take the Vin# to the car of interest to a local franchise dealer that handles Chevys, and get with the service department in that dealership and ask them to run a Warranty Repair History for you.  That will be the best indicator of what has been done to the car in regards to the possibilities of it being a lemon.  Understand that you should also have the remainder of the factory warranty.  A lot of cars start out with rental companies, and that does not worry me....but I would still check carfax and the warranty repair history on the vehicle, just to be sure.
The cons of Rental car companies are simply this, those persons renting vehicles, could not care less about the vehicle when they are driving it.  The Pros are they are supposed to be maintained at dealer specifications....now whether that actually happens or not may be another question but fact of the matter is this, if the car checks out at a mechanic shop of your choice, the carfax is good, the warranty repair history is decent, and it is a GM certified car, I would have no problems making the purchase.
I hope you find this helpful and please let me know if I can be of further assistance.  OH...one more thing, when you run your carfax report, there is another option in there to check the "General" reliabilities of said cars as a whole, that may be useful as well.
Good Luck,
Jay