I just had a Bravo DVD player installed in my car. It has an SD slot & a USB flash drive input. The manual says that it reads mp3, wma, mp4, etc... I have successfully tested mp3 audio files, but I cannot get it to recognize mp4 video files. I've tried both SD & USB inputs, but no luck. I've searched high and low on the internet for help, but found nothing. All I want to do is put some digital movies on a flash drive and play them over the monitor.