It can store up to 32 images I think it was confirmed? No need for USB once the wallpaper is stored in MFT.
Once upon a time I had:
2012 SGM SEL Sedan Job 1 BD 6/2011
FSWERKS Cool-Flo w/ ITG Filter | FSWERKS Stealth Exhaust | 17x7.5 Axis Sport XMX Graphite wheels | Eibach Sportlines on Ti Handling Pkg bits