Hennessey is adding an open air version of its Venom GT for 2013.

There isn't much room for the 1,200 horsepower Hennessey Venom GT to grow in power, so the Texas auto tuner has decided to improve the two-door the only way possible - by popping the top.

Hennessey has announced that it will offer a Spyder version of its mighty Venom GT for the 2013 model year. Buyers of the 2013 Venom GT Spyder will have better access to the car's exhaust note, but it won't come cheap - with a list price of $1.1 million, the Spyder is $150,000 more than its coupe counterpart.

Hennessey has yet to reveal the Spyder's details, but some changes could be in store. The Venom GT coupe boasts a top speed of 272mph, but that figure could be capped for the Spyder to ensure its removable top doesn't fly away.

Hennessey only plans to build five total examples of the Venom GT in 2011, so the Venom GT Spyder figures to be one of the rarest vehicles on the road.