Have you tried an other dealer. From my reading here, I read the flash should turn the HU internal amps off. You will lose bass, but that supposedly gets rid of the distortion. There is also a sticky here to print out and carry in and tell them , this is what you want. Hopefully you get it worked out.Nothing wrong with responding, it's good to know that the Boom! upgrade has worked for somebody. It's possible that your dealer knew how to set it up and flash it to make it sound good. I have no clue other than it didn't work out for me and now it's been hell trying to get something worked out.