Which will yield better sound quality in an AUDI (A4) with an OEM head unit?
1. concert head unit (no most bus) to oem amp to high level inputs of helix dsp to aftermarket amps and speakers.
2. multimedia head unit (most bus) digital signal to mobridge da3 to aftermarket amps and speakers.

It would seem that option 2 would be easier to setup since the input signal to the mobridge would be digital with no eq applied.