I guess this is now my official build thread. Certainly, It's not on the order of Neil's build, but as a mere mortal, I'm having fun.
Here's a picture of my current interim mess. I bought the first of several cheap DAC's and hooked it up via the Toslink output on the MB. Works great. I also was hoping to use the digital in/out from the SoundBlaster USB soundcard to integrate a physical volume control, but had no luck. I think it'll do it, but the SoundBlaster settings and documentation have me baffled. I'll give it another try later.
Next is an appropriate case and PS. I'm hoping my GTI has enough depth in the radio hole to accommodate a double-din PC case, but I'm doubtful. I may pull the radio today to have a look-see.