I can confirm the 86 comes with no stereo in Japan, you choose one from the list (or don't have one installed, of course, but that won't be popular, I don't imagine). Prices start from a few hundred bucks and go up into utter nosebleed territory -- we're talking a few thousand -- for the bluray mybook million-gigabyte special. With nav as an extra price for the maps!
that said I'm more interested in smoker shields. I don't smoke but they keep rain out of my face, I'm a sucker for keeping the windows open a little. Or maybe the "driving support" system which tells you if you're close to other vehicles. On all four corners.