smoke screen? ok seems a little over the top to me but this is your rig and your turf you know it best..how about a small plastic container such as a soda bottle with used motor oil in it and a cork with a string that can be pulled..mount device to the under side of your floor board using metal straping ..make sure that the open end is placed right above your muffler or slightly forward of it since forward movment of the vehicle will make the oil fly to the rear of the vehicle..oil on a hot muffler will give you smoke