Obama's new presidential limo is built like a tank, looks like a Cadillac

When Barack Obama hops into his presidential limousine after his inauguration on January 20, it might be this brand new rolling fortress that's part car, part truck. General Motors might be about to financially tank, but it's still putting the finishing touches on this real-world tank that'll soon be shiny and bear the presidential seal.
Most of the specs of this car are top secret, but a few tantalizing details are floating around, such as the five-inch-thick windows that are about half as transparent as regular glass and can stop projectiles from assault rifles, rocket-propelled grenades and high explosives. It's also said to be built of a combination of blast-proof ceramics and exotic metals, and certainly won't have a convertible top or sunroof.
While GM's trying to make it look like a Cadillac DTS, it's based on the company's line of heavy-duty 2500 trucks. For a fast getaway, it must have a giant engine under the hood. Because the presidential motorcade typically uses up to six decoy vehicles, there must be a mini-fleet of these behemoths on their way to the White House before too long.