It isn't so much a car as an armoured personnel carrier wrapped in Cadillac bodywork. It is code-named "Stagecoach" but given its weight, wheelbase and bunker-like level of protection, Caddy One has been nicknamed "the Beast."
Built by General Motors, the latest in a long line of Cadillacs to join the First Fleet over the years, it has carried the first African American president since his first ride down Pennsylvania Avenue to the White House after his Jan 20, 2009, inauguration on Capitol Hill.
"Although many of the vehicles' security enhancements cannot be discussed, it is safe to say this car's security and coded communications systems make it the most technologically advanced protection vehicle in the world," said Nicholas Trotta, who was assistant director of the Secret Service Office of Protective Operations when the limo was pressed into service.
GM and the Secret Service zealously guard the car's specs and secrets, its security and coded communications systems that put phones, satellites, the internet, in short everything at his fingertips, according to the Secret Service Office of Protective Operations.
Estimated to cost $300,000, the redesigned car, says the GM, "is a fresh, more modern, more expensive" version of the Cadillac DTS that carried President George W. Bush from his second inauguration in 2005 to his last day in office.
Limo One is believed to weigh between seven and eight tonnes, and spy shots suggest it rides on a GM medium-duty truck chassis propelled by a diesel engine.The body is sheathed in military-grade armour as much as eight inches thick on the doors, each of which weighs as much as the cabin door on a Boeing 747.
The armour reportedly is a mix of dual-hardness steel, aluminium, titanium and ceramic. The windows are ballistic glass said to be five inches thick.
There's probably a woven Kevlar mat covering the floorboard to protect the car from blasts, according to the Los Angeles Times. The cabin is believed to feature a sealed air recirculation system to protect its occupants from chemical attacks.
Still, despite being at least as secure as a hardened missile silo, GM says Caddy One features the same hand-sewn leather interior as the one in the CTS available at the local dealership. It also features a 10-disc CD player.
The car is one of a small fleet of what is believed to be no more than 25 presidential limos General Motors built for the Obama administration, according to Detroit News.
Although presidential limos have a lifespan of about a decade, the commander-in-chief gets a new one about every four years. Hand-me-downs are used to carry the vice president and visiting heads of state.
But Obama has also used the limousine of his predecessor consistently, during visits nationwide and internationally.