I've got a refurbed F90bt that I bought a few weeks ago on ebay.
Installed it in my wife's car last week, bought a 32g SDcard after I figured out that the usb connector seems mainly useless (64g usb stick won't work, usb hard drives don't work well due to power, etc)
I've got a 30 gig music collection on the card, off the bat it seemed to work but I did some reorganizing on the card today and when I put it back in I noticed that most of the directories only listed the first song in each directory.
I don't have any files in the root. Its organized by \Artistname\Albumname\Song.Mp3
I'm reformatting the card right now as Fat32/4kb alloc units. Had to do a full format as the quick format failed.
Anything else I should know/try? She leaves on a solo roadtrip with our two kids in the morning and I'd like to have this working for her before she goes.