I guess Sony wasn't the only collab, it looks like Sharp was in on it with a portable DVD player from 1999. Thanks doaudiojp!
A just posted a killer brochure from 1985 for the Sony D-50 in that thread if you like looking at eye candy. Doing a little diving I found this video, I think the guy is former head of Bose? The translation isn't complete but he does talk about the Bose and Sony collaboration. Apparently Sony had such a good audio reputation that other companies were looking for these co-ops. I just found these videos, there might some other gold in them since their named after the big dog at Sony. If you go to settings you can auto-translate into your langauge.