This is my biggest gripe about the play-from-USB feature set. I want an arbitrary subfolder depth in the system so that I can properly organize my music accordingly.
After that, I want a simple selection mechanism to choose what folder(s) to pick for randomization.
I also use a 32GB drive. This solution + DriveSort is probably what I'll end up using for a while. My worry about DriveSort is that I think it'll ultimately wear down the life of the USB stick.
Although, I am curious to see if I can play with a programmable USB device that presents itself as a Mass Storage class device, with underlying logic that's actually smarter than that. Perhaps a Raspberry Pi model A, if they release those sometime. I heard the Raspberry Pi model B won't work like that since a USB hub is built-in, therefore limiting it to act only as a USB host, (consequently preventing it from acting like a USB drive).
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On a totally different note, my car+USB stick combination has required unplugging and replugging in the USB stick on almost every other time I start up the car. I'm not sure if this is just my USB stick (I'll test on a few others sometime), but if it presents across multiple USB sticks, I'll probably ask the dealer to check it out. It gets annoying after a while...
-The Doctor