Yes they do (LX package). Frankly, you can put the same parts together yourself for less money. By all accounts they've been on the up-and-up for a while now, but they had some questionable business practices for a while that, coupled with their pricing, make me hesitant to ever consider them for work on one of my vehicles. Your mileage may vary of course. One advantage is bragging rights... "I have a Hennessey car!"
Interesting too... on their specs page:
They list a 1/4 mile time (11.3) that's slower than what PPP hit on all stroker no turbo or nitrous (11.24), and slower than jmatt hit on just nitrous (11.17 I think?). Seems backwards considering the car weighs a couple hundred pounds less than an LX, doesn't it?