It's actually a lot less energy than it sounds like. The temperatures will hit 10-100 times the temperature of the sun, but the density inside will be very very low. This thing couldn't vaporize a car.

Remember, this is only a 500 megawatt device, and the reaction is so unstable that if it somehow escapes the containment of the device it dies instantly. It can't "run away" like some fission reactions can.

edit: Not actually sure how much energy it takes to "vaporize a car in seconds." In terms of energy this thing is roughly equivalent to any other fairly large power plant.