A neighbor of mine, a young kid with a V6 Camaro tried to wire one of these up himself.
He used the LP bottle from his parents gas BBQ grill and tapped it into his tail pipe with a nipple thingie.
Then he bought a push button ignitor for a gas grill and mounted it next to the gear shift lever.
It worked, sort of...
The flame just bubbled out of the tail pipe.
There was no "throwing" or shooting force to the flame.
I gotta say, in terms of running the lines, he did an excellent job.
(I was waiting for him to set his place on fire; which he did, but that was a different incident and totally unrelated to his home conceived exhaust flames.)