Wanted to improve something by a subwoofer the standard speakers in my Golf5. The installation of the subwoofer was easy. Power transferred to the battery and the RCA cable to the radio. And then it could go. I think the subwoofer makes a mega bass, the volume of the bass've just time to half, yet my rear view mirror wobbles when driving extremely. The subwoofer is very good and clean bass by itself .... you should however be individually adjusted with the phase shifter and the frequency, both are adjustable on the subwoofer. I would buy the subwoofer at any time and can only recommend it !!