BSR. 1  A Sweedish company that produces engine tuning kits for a wide variety of cars, including Saab, Volvo, Seat, Fiat, VW, BMW, Opel, Mercedes, and Audi. BSR's Protable Program Carrier (PPC) plugs into the car's On-Board Diagnosic (OBD-II) Port (where the mechanic scans engine codes) and re-tunes the engine computer. The engine computer can also be de-tuned back to factory settings. The PPC is married to the car that it first tunes (sorry, you can't pass it around).