Just for future reference for people who don't know, to make an aftermarket radio work with the DSP amp, all you need to do is code the DSP amp to mid_basis instead of bord_monitor. It will no longer shut off the sound after a few seconds. Also, you can wire up a DSP MID (bought from a salvage yard or ebay) to ibus, power and ground and be able to set the DSP settings, then disconnect it once set. Use the high powered front left and right speaker outputs to the DSP amp inputs from the radio module and fix the audio level on the head unit, then use the steering wheel controls to control volume.

This works great in my 4.8is with a Pioneer AVIC-6200NEX head unit. It should also allow any of the non-DSP, non-Android head units to work with DSP amps (Dynavin and other ones that fit the space, but don't have a "DSP" module). It also works with my NBT system in both of my e39s with DSP.