WOW, I brought in my Mercedes 2014 SL550 that came from the factory with a Bang & Olufsen upgraded stereo, that produced sound almost 100% from the front speakers, it was designed for surround sound and the rear speakers only worked with a DVD Audio disc with surround sound. Needless to say the stereo was a big disappointment. So I asked Don at Soundwerks if he could fix it so it sounded more balanced between the front and rear speakers. Don worked with our local MB dealer, obtained the electrical schematics, installed another amplifier, did some rewiring etc and presto! The stereo sounds AWESOME. These people obviously know what they are doing. I could not be happier with their work and dealing with them. Very professional, honest and super experienced. HIGHLY RECOMMEND.