We have 2 of those.

The 1st one:
- When I plugged in a USB flash drive having more than 20 songs, it wont play at all. 5 or less pwede. Advice you insert an MP3 player instead

The 2nd:
- you can plug-in an SD card.
- weak signal, may static tuloy yung sound na lumalabas
- signal is lost in covered parking areas