I'm a big fan of high-quality digital music streaming providers such as Spotify and MOG, and both offer up to 320kbps bitrates now over 3G/4G, but until now I have not been able to successfully integrate that option into my car stereo system. In the past I tried to connect the analog audio out from the iPhone dock connector via an RCA cable to the MS-8's AUX input in the trunk, but the RCA picked up a LOT of noise. I like the idea of having a digital connection between the iPhone and the trunk and having a third party DAC do the DA conversion instead of the iPhone itself.
I did some researching and found a unit called the Pure i-20, which is primarily designed for home use, but I believe it will work just as well for this purpose.
The unit extracts the audio signal digitally from the iPhone and then converts it with its own (supposedly high quality) DAC and outputs the signal through RCA connectors.
So I think I'll give this a try. I will use a standard iPhone sync cable to connect to the iPhone, then a male-to-male USB extension cable to the trunk, then another iPhone sync cable and finally a male-to-male iPhone synch connector to connect to the i-20. Between the i-20 and the MS-8 a standard RCA cable into the MS-8's AUX input.
Should be fun!