I have a 430 RBZ and I plugged a 64G sandisk cruzer low profile USB stick and the radio reads some of the mp3 files but some folders show they're there but the music files never populate so I thought maybe the radio won't accept sticks that size but I can plug it in the USB connection in the glove box and it reads all the music files but they are not grouped into folders. Every once in a while using the front USB you touch on a folder and wait and it will populate, other folders you try the mp3's never show up. frustrating.