How to Get MP3s Working on the Audi MMI System?

[A Winner Is You]

I have a 2012 A5 with the B&O MMI audio system, and 2 SD card slots. Great, as I can put my whole music library on there. When I first did this I found any MP3s played fine, but any MPEG-4s (which I would have ripped from CDs in iTunes) weren't recognised at all. So I used VLC media player to convert all of them over to MP3, which the car now recognises. But it won't however play them, it just jumps straight to track 5 and does nothing. Any ideas what program I can use to try again and get the car to recognise them?