Honda/1BU5/serial number
from HTYP, the free directory anyone can edit if they can prove to me that they're not a spambot
To retrieve the serial number: with ignition on and radio off, hold down the "1" and "6" keys simultaneously and then turn the radio on. The serial number will immediately appear on the radio's segmented LCD display.
There is a visual demonstration of this technique on a different model of player in this video from 2014.
