I visited Leah and Jake in St. Thomas in May 2010. Carnival was in full swing. Their roommate was part of a sound car and you can see him get up and dance on the back of the truck once he spots us.
These sound systems were the loudest outdoor experience I ever had… until Burning Man. The quality of the sound does not come across as the cheap microphone on the camera was overloaded. While I did not like the actual music that was playing, the clarity was pretty impressive.