First pic: Hennessey Venom GT Spyder

As this clip testifies, it isn't terribly difficult to hear the 1200bhp twin-turbo V8 in a Hennessey Venom GT. Which is why it's utterly ridiculous that the Texas-based hypercar builder has removed the roof on its 2013 Venom GT Spyder.

So, how does one remove the roof on a 250mph+ sort-of-Exige-but-not-really-based mentalist? It's a traditional removable hardtop design - the centre section lifts out, offering the Spyder's inmates unbridled access to the sky. And tinnitus.

Hennessey CEO, Don Goldman, says: "With the hardtop in place, the Venom GT offers a very visceral, raw, driving experience. With the hardtop removed, the wind and growl of the twin turbo V8 will offer our clients an even greater driving sensation."

Said V8 is, of course, a beefed up twin-turbo 6.2-litre LS9 V8 from the Corvette ZR1, which produces a hoofing 1200bhp and 1155lb ft of torque.

Want one? Hennessey plans to build five Venom GTs and two are already spoken for (including the car pictured). If you want one of the other three, you'll need £700,235. Want one but don't have £700,235? Stick a Dyson Airblade up each nostril and listen to this video on full blast.

And if you need a further reminder of the sheer visceral thrill of this car, then check out the time we drove one against the SSC Ultimate Aero in America...