cammusic

I prefer to listen to mp3 files in the car from a USB drive. I have a rather large collection and it seems to be too large for the system to handle. It seems like Chevy has fixed a number of issues regarding listening to music via USB drive (indexing is faster, and playback resumes where you left off after shutting off the car), but I still can't get the car to recognize everything on the drive. Does anyone know if there is a maximum number of songs it can index? Or maximum size of drive? I have like 30,000 tracks taking up 155 gigs on a 256 gig USB stick.