I know my streaming sounded distorted before I fixed the cable.
What head unit do you have? I take it yours is under the drivers seat which may make it a bit more awkward to check the cable..

I have just checked the ring tones on mine and they seem clear.
I have noticed that I have to turn the phone volume up to near max to hear the other person but it is not distorted.
I have gone into the adaption using VCDS to modify the values but it crashes each time.
Maybe the module is that new the coding hasn't been worked out yet.
Maybe you could try the factory reset on the unit to see if that helps.
Steve has done the same as you, I think, changing the Rsap Module for the 9W7.