Performance Improvements Hamilton is your source for performance auto parts, accessories plus the parts to give great fuel mileage for street, custom, sport compact, tuner, truck, and racing vehicles in Hamilton, Ontario, Canada. Some of the car parts Performance Improvements Speed Shops Toronto sells includes: Headers, exhaust, fittings, fuel cell, mufflers, supercharger, turbo, engine, intake, lowering springs, synthetic oil, tires & wheels and much more, from a wide variety of companies.