Similar to MarkZ28's smokescreen...
I was nursing a sick turbo Miata back from California. It had no piston rings left, took us something like 3 gallons of oil to bring it back. Kids, don't let your machine shop use aluminum oxide as a blasting media on your intake manifolds. Anyhow, anytime I got on the throttle to any extent it would throw a huge smokescreen. I was passing a truck while trying to avoid going over about 1/4 throttle. I was over the speed limit when a yellow Integra pasted itself to my rear bumper, close enough that I don't think I could have seen his front plate. So I let the car have full boost, and he completely disappeared from view in the resulting smoke cloud. My boss Bill just about killed himself laughing, he saw it coming.
I once hooked up the nozzle from a cheap squirtgun to a windshield washer pump and aimed it to the right at about ankle height. Didn't throw much water, but it sure puzzled some pedestrians.
