We've the larger Uconnect (without satnav), you can connect your iPhone via usb (if you have) and it works fine it but I copied my whole iTunes library to a tiny usb drive which the car recognised immediately. Cool thing with that is it means the music is available to both my wife and I. Pulls in play list's, album art work the lot.
Great stuff, the iTunes copy works really well for me, a pain to update perhaps but I'm at the stage where I buy an album fairly infrequently so it's not too onerous.
I went for a tiny Sandisk Cruzer 64gb, which is impossible to see from the outside (and even when sat in the car if you don't know it is there!). The odd red light for reading when you unlock the car but again, you'd think it was an alarm if you didn't know.
FYI if you guys decide to use a SD card for music the official max size is only 32gig due to file format. However you can work around this by using 3rd party apps and so I have 128gig SDXC card with all my music.