I heard about that , he was told that's how you fix dents, someone told him "Just blow into the exhaust pipe as hard as you can and the dents will disappear". Apparently a passer-by stopped and asked what he was doing, he replied "Getting rid of the dents by blowing into the exhaust. All the air will go inside the bus and pop out the dents." The passer-by laughed "You're a fecking idiot, that's not how to fix dents , you gotta close the windows first so all the air doesn't escape."
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Another man's freedom fighter, one man's terrorist is - Yoda (probably)