I don't have Nav either. But if you format a USB thumb drive to FAT32, you can use the USB plug in the center arm rest to put your music on. You can't save to it (must be a Technology package feature with the Nav) but at least you can play your tunes.
2013 F30 335i | Sportline | Imperial Blue Metallic | Black Dakota | 6-speed | HK | Cold | Premium | 19" Staggered Sports | M-Performance Exhaust
2009 E90 335i
2007 E90 328xi