Taken from Reddit - "Taken from the manual. "In party mode, the sound volume from the speakers on the back door is bigger than in base mode. (The output from the speakers on the rear doors will be transferred to the back door speakers.)"."
A noticeable difference in sound, it seems to adjust the equalizer for a much fuller sound. I could see turning it off when others are in the car for easier conversation.
Lol, one day that horn will go on the 40.I think you should re-wire this button to play the Oooga horn.