I was just getting ready to ask this same question. I put a DICE in my wife's 2004 X5 with DSP and the engine noise is so bad I wont even listen to the Ipod when I drive it. It also makes a light clicking noise (some songs are worse than others. I'd love to know if the re-grounding really works. I'm pretty close to getting an OEM adaptor or putting the changer back in.