$18k for headers, exhaust, and a fake tune is a joke. If you want, send me your car and I'll give you the same tune for just $100.
This video is just more Hennessey shenanigans. First off, their baseline dyno video has the car with 30 more rwhp than the after header/exhaust install.
http://www.youtube.com/watch?v=wLQfPhFICvM
Then apparently in the new video, the car only makes just over 500 HP? I'm telling you this is the way Hennessey will sell his tune that actually can't be done at all. He will show you a 503 HP reading on the dyno and then miraculously you will make just more than the true stock reading.
I know you're new to the Viper world, so I'll do you a favor. Just Google John Hennessey and Viper's and you'll see what a crook he is. This honestly makes me sick...