It's an ultra-tricked-out Caddy, dubbed "Cadillac One."
Finding out details about the special car hasn't been easy, but CBS News correspondent Kimberly Dozier has done some digging.
Details about the new limo have been closely guarded. It's been kept under wraps -- literally -- and will be until it's shown to the world sometime this week.
"It's a new look. It's a refreshing, kind of expressive, more vibrant new look," says Cadillac spokesman David Caldwell.
The outside will look different. But what else has changed from the last Caddy-in-Chief?
The folks at Cadillac and the Secret Service won't say much. All they tell Dozier is that the windows on the new car are bigger and the seats are made of hand-sewn leather.
"The technical aspects of the vehicle and its functions," notes Caldwell, "are things that are done very much in secret, and private, and they shall remain so. In fact, I can't even tell you some of the materials that have been used on previous presidential limos!"
The first presidential limousines actually came straight off the factory floor, with little or no modification, points out presidential limo historian Gregg D. Merksamer. "The only thing that would have made them different from a limousine that anybody else could buy is there would have been a presidential seal on the door," Merksamer says.
The Kennedy assassination changed all that, Dozier adds -- a moment of tragedy that transformed how presidents traveled for good.
"The president's car went from being a parade vehicle, an open car, to being a protective conveyance -- something that was armored," Merksamer observes.
Think "luxury tank," made to withstand any number of scenarios, Dozier suggests.
Auto experts say safety features include rocket-resistant armor, six-inch-thick glass and run-flat tires. The rest is anybody's best guess.
To see the CBSNews.com Special Report: Inauguration '09," click here.