Cheap gasoline prices, an increase in miles driven and an aging fleet of cars on the road have helped leading players such asO'Reilly Automotive ( ORLY ),AutoZone ( AZO ) andAdvance Auto Parts ( AAP ) maintain decent growth. F orget the current banner year for new-car sales -- auto parts retailers are forging ahead undaunted, benefitting from a host of favorable industry trends. This Do-It-For-Me (DIFM) side of the business has provided an additional revenue stream for auto parts retailers, which used to rely almost exclusively on the Do-It-Yourself (DIY) market.