Buying a used car has several advantages over buying a new one - namely the price. Yet there's no denying that the peace of mind that comes with a manufacturer's warranty is a nice perk for those who buy new.That's where Certified Pre-Owned (CPO) vehicles come in. Nearly all major automakers maintain some type of program that allows them to resell their used cars. Vehicles that are certified by the automaker are backed by a warranty. This allows the manufacturer to also offer financing for the vehicle, just like a new car.To qualify, a used car must be subjected to an independent refurbishing process, where it's restored to "like-new" condition. So getting a CPO eliminates much of the worry that comes with used cars, as it's highly unlikely that the car will be a lemon, and if it is, it has the manufacturer's support behind it.The trade-off is that these cars fetch a higher price than non-certified used vehicles. Yet because they're still cheaper than new cars, many drivers see CPO's as a great compromise.Drivers should be careful, as some dealers often offer their own versions of CPOs. But this typically means that the car is inspected by the dealer's in-house repair shop, and while it may come with a warranty, its one that would only be honored by the dealer, not the manufacturer. There are also a few independent certification bodies that operate outside of manufacturers and dealers and could offer a better deal and possibly higher repair standards.MSN Autos recently compiled the top 10 CPO sellers of the first half of 2010, according to data collected by the manufacturers. The list could provide drivers with some clues as to which vehicles have become popular because of the program and what they should keep their eye out for if they choose to go this route.Honda had a strong showing on the list. The Odyssey, at number nine, was the top-selling minivan, while the Civic and Accord placed fourth and first, respectively. These cars hold their resale value well and are already known for their reliability. Yet the news source notes that drivers should beware, as CPOs from Honda with low mileage can come very close to the price of a new car.Honda's chief rival Toyota also had three cars on the list, with the always popular Lexus RX crossover joining perennial best-sellers the Corolla and Camry. BMW took up two spots with the 3 and 5 Series sedans, and the news source notes that a several-years old 3 Series CPO makes a luxury car affordable for many drivers.