And don't we all.
John Hennessey has a pretty easy philosophy to understand. He just wants to go faster. Usually this means squeezing as much power out of an engine as he possibly can, and this is also what most of Hennessey's customers come to the tuner for. Those who simply want their cars to look unique take them elsewhere. But when it came to the Venom, they already had an engine which they'd squeezed a hell of a lot of power out of, and then they went in search of a sufficiently light car to put it in.
The idea to put a Viper engine into a Lotus apparently started as joke, but once it started looking like it was actually feasible, it became too popular to not build the car.