I read this thread but there is one big difference with MFT versus Sync only. MFT supports exFat. This format allows MFT to see the flash drive as an external hard drive. A friend of mine with an ST was having the problem with MFT indexing and building voice commands every time he started the car. Changing to exFat seems to have resolved this for him.
Also, there is a far easier way to create playlists that work using a software program called Media Monkey. The biggest difference is that Media Monkey can manage your collection, devices, and autosync music and playlists. It will basically make managing your USB drive like syncing an iPod with iTunes. All updates and new playlists can automatically sync and update your device. If you pay for a registered version of Media Monkey, you can also create Auto Playlists based on multiple criteria. There are ways of getting Windows Media Player to work, but the program is god-awful slow at both managing the library and syncing the device.
Almost forgot, this thread has already been created. Here is the thread if you would like to link from your thread:
Sync playlists to USB Thumb drive for Ford Sync