Taken from the following link:
The new Cadillac model of the presidential limousine was made by General Motors Corp and unlike other presidential limo models it does not have an official model name, The Detroit News reported last week . By some accounts, it’s called “The Beast.”
The vehicle includes heavy armor that is reportedly at least 5 inches thick, run-flat tires, bulletproof glass and a completely sealed interior to ward off a chemical attack, the paper reported. It also has electronic communications equipment.
And here’s a picture of it:
It has nothing to do with the Constitution, but I just love this “top secret” stuff. Dick Cheney’s “undisclosed location,” the underground White House… I find it very interesting.