Thanks for the reply my friend! I guess I should have been more detailed in my original post but the issue is when I connect my Android (HTC Thunderbolt) to the stereo in my car via USB I can only use the stereo to browse and it only recognizes folders containing mp3's (not playlists for some reason). Thus, I'm trying to somehow get MM to sync songs added to the library in the last 7 days (for example) into a specific folder (like "Recently Added") on my Android.
This is the heirarchy I have now under "Sync Music files to" (which my stereo likes):
I tried what you suggested (creating an Auto-Playlist of songs added in last 7 days) and using this hierarchy:
My stereo would show the <Playlist> folder names, but says they don't contain any music files...