I hardly ever do that. Don't generally see the funny either.
Although there was this one time riding in the back seat of my parents car... We were driving up into the Rocky Mountains and at a certain elevation the lack of pressure caused me to start letting them loose like they were timed to my breathing. Still cracks me up when I recall us rolling along with all the windows down and 2 feet of snow on the ground
That was some National Lampoon stuff right there.