When cars are brought in for repairs, the type of replacement parts you get can depend on the service department you visit. Local dealerships use Original Equipment Manufacturer (OEM) parts, whilst you may get a choice between OEM and aftermarket parts from independent shops. OEM parts are built by the original car manufacturers, meaning they are generally the same part as that found in your vehicle. Aftermarket products, on the other hand, are ones generally produced by a company other than the original manufacturer. Typically, aftermarket is cheaper than OEM.