I didn't get a chance to finish this but they cover it at the begining of this episode (I got through the Crossover set-up)
I was thinking about something like this for my Toyota Highlander but then the proverbial rabbit hole got deeper and somehow this didn't seem like enough or more to the point I am already thinking about the upgrades to a build I just started so that would free up an AudioControl D.6-1200 for the Highlander which I would use to drive AF GS series
https://www.youtube.com/watch?v=CNPjM3Xe7bI