The Fuze has two USB modes :MSC and MTP. Those are the names of different connections. A computer can only see one mode at a time–when you are searching, it is as if the other one does not exist. And various programs use different modes.
MSC mode makes your Sansa work like any other drive on your computer. You can see two drives in Computer or My Computer: one for the unit, one for the card slot. You would open the drive and drag over the folder of mp3s.
MTP is made to work with Windows Media Player and Rhapsody.
You have the music listed in Rhapsody, and you send it from Rhapsody.
So using Rhapsody to transfer the tracks means your car stereo probably won’t see them, because your car stereo wants MSC.
MTP mode is necessary for some music-subscription services, because MTP mode also transfers hidden Digital Rights Management information. But it is not necessary for plain old mp3 files.
I suggest you connect to Rhapsody and take the files off the unit (in MTP mode).
Then go to Settings/System Settings and switch to MSC mode.
Find the files on your computer just by using Windows Explorer or the Search function, open the Sansa and drag them in. Then your car should be able to see them.
You can’t just leave the Fuze in Auto Detect because it will go to MTP first.
There are free music-library programs like Rhapsody that work in MSC mode, including Media Monkey
If you do decide to use Media Monkey–try it first–then do the tweak explained here