Motorcar Parts of America, Inc. is a supplier of automotive aftermarket non-discretionary replacement parts and test solutions and diagnostic equipment. Its Hard Parts segment includes light duty rotating electric products, such as alternators and starters, wheel hub products, brake-related products, including brake calipers, brake boosters, brake rotors, brake pads and brake master cylinders, and turbochargers. The Test Solutions and Diagnostic Equipment segment includes applications for combustion engine vehicles, including bench-top testers for alternators and starters, equipment for the pre- and post-production of electric vehicles, and software emulation of power system applications for the electrification of all forms of transportation (including automobiles, trucks, and electric vehicle charging stations). Its Heavy Duty segment includes non-discretionary automotive aftermarket replacement hard parts for heavy-duty truck, industrial, marine, and agricultural applications.