Honda Acura 92-04 / Mercedes 94-98 (GROM-USB3-MBUS) firmware version 58 has issues with buffering on iPOD USB connect.
Each song stutters and does not buffer at only the beginning of each song. No issue with Bluetooth streaming.
I am using a iPOD nano 7th gen, via USB connect.
I had to downgrade down to version 57 in order to fix the issue. (for now)