All in all, AutoZone trades with a lower P/E than O'Reilly yet what appears to be the same or better growth prospects. Both are great companies, but I lean more toward AutoZone as the better buy since they both have similar market caps yet AutoZone has less speculation built in or needed in its stock price.
Bosch is another good brand that manufactures aftermarket car parts. If you are in need of some aftermarket shock absorbers, look no further than Koni. Other great companies that appear on this top aftermarket car parts brands list include Promotive, Dynomax and Carquest.
AutoZone is a good place to walk in and get parts from. If you don't need the parts right away, however, you can look on RockAuto.com and see if your parts are there. They may be a little cheaper than AutoZone. If you need them now you can get a reference price to walk into the store with.
It's just fine for buying auto stuff IMO. As long as you're sure about what you're getting, why not? You can't wrong with something like an air filter if you look up the Fram part number on their website first. You will generally find the same name brand parts as the parts stores, and plenty of no name knock off.
The Carquest brand is owned by General Parts, which was just acquired by Advance Auto Parts. CORRECTION: This article erroneously stated that AutoZone has 42,000 employees. The correct number is 72,000 employees. AutoZone has 5,210 stores, 72,000 employees and $9.25 billion in annual revenue.