I recently installed a GROM-MST4 in my 2009 Volvo V50.
I'm using it to play Ogg Vorbis files encoded at quality level 10 and stored on a USB SSD.
I've got two glitches to report:
1) the unit sometimes stops playing just after the end of a track. Prev/Next track won't resume playing. To resume, I have to skip back and forth between albums.
2) some albums are played low pitched (should I say 'slow motion' ?), despite being encoded with the same encoder/settings than the rest.
Those music files play fine on computers.
Sorry for my poor english.