Hennessey's 600HP RS6 on here!
It will only set you back about $30K (USA).
I would most def want to ride it before getting this system unleashed on my beast.
We should contact them, and do a field trip. Imagine 10 RS6s showing up at Hennessey's place, with appointment of course, to really see if the system is worth it. I think they'd be impressed.