100% guaranteed working amp Genuine BMW part. Before ordering send me a message with VIN chassis number of the car to confirm compatibility. Programming/coding is included. Amplifier will be reprogrammed and tested on work bench to ensure quality (VIN number required). THESE ARE PROBLEM ON CONVERTIBLES WHERE THE WATER LEAKING THROUGH BOOTLID RUBBER SEAL DRIPPING ONTO THE AMP IF YOU DO HAVE THIS PROBLEM FIX THE LEAK FIRST OTHERWISE IT WILL LEAK AGAIN AND FRY NEW AMP. Any questions please ask