Does anyone know of a plug in for Motion or how to create a heat haze effect that comes from a jet engine or in my case a furnace?

wow i feel a little late for answering this lol...but you dont really need a pluggin for that. like in shake, you can use a filter that does what you want it to do throughout the entire image...mask off the image to the area you want it in...then apply it back on top of the original footage. some sort of wave or ripple might work.