Flaming exhuast fairly simple idea many ways to do it with differant materials but basic one is a propane tank running a solinoid with the switch in the dash and the hose from the tank to the exhuast after the cat converter then add a spark plug or glowplug to the end of the exhuast with a switch running to the dash so you flip the propane on get a spark or warm the glowplug and as you rev your engine the flame will shoot farther.