I have the following for sale:
Mcintosh MX4000 Head Unit
Mcintosh MDA4000 Outboard DA Converter
Mcintosh MPM4000 Analog Meter Module (which looks great in the dash below the HU)
Mcintosh MCD4000 6-disc changer
All of this was installed in my GTIVR6 with 4 2-Channel Butler tube amps, Dynaudio 3-way front stage with 8" mid-woofers, in sealed enclosures, and a single sealed 12" Alumapro sub. Everything was removed from the car about 7 years ago and has been sitting in most, if not all, of the original packaging since. The goal when building was all about sound quality - it was amazing.
Let me know if you are interested. It is very difficult to find all of these items in good working condition.