All parts bought through the dealer are covered by BMW's 2 year/unlimited mile warranty on the part and the labor (at any dealership in the US). Doesn't matter who installed it. One very good reason to get stuff from the dealer About 5 years ago I bought a remanufactured trans from the dealer, had it put in, a month later it died on the highway. Towed the car to the nearest dealer and warranty covered the entire thing.