It is good to be the president. It's better to be the king. But it's best to be the Pope. And that's not just because figureheads live in the power and the light, juggling fame and glory.

No, the long list of privileges includes rides that are, well, regal. In fact, some of the most extensive collections of lavish, unique automobiles around the world belong to heads of states, not celebrities or rock stars.

The typical wealth accoutrements are all there. On-call chauffeurs? Check. Custom detailing? Check. State-of-the-art security? Double- and triple-check. But the best part may be the sticker prices, or lack thereof. Carmakers frequently donate their vehicles for presidential and royal use.

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That helps, but many heads of state, monarchs, and high-profile elected officials unabashedly display nationalistic tastes when choosing an official ride. Most favor auto makers from their respective countries to supply their cars.

One-of-a-kind

The Imperial Household Agency of Japan, for one, just received delivery of a new Toyota Century Royal limousine last month that's worth north of $460,000. The model used by many in the country's political class is extremely rare. Fewer than two hundred Centurys are sold each year. They are not available in the U.S.

Like many royal rides, this Century is one of a kind. It's fitted with the country's only 5.0-liter V12 engine and features top-secret fuel-efficiency technologies in addition to an interior made of environment-friendly materials. It is also the only road-going limo in Japan without a license plate -- even more proof that the royals live by different rules.

The British royal family, unsurprisingly, cruises around in Rolls-Royce, Land Rover, and Jaguar models, even if these quintessential British brands are now owned by BMW and Ford Motor (F). But these aren't your run-of-the-mill ultra-luxury editions. Queen Elizabeth's custom Bentley -- which was made by Volkswagen -- is estimated to be worth over $750,000.

A gift from the car manufacturer and British parts suppliers for her Golden Jubilee four years ago, the state limousine is used for formal events, as are a series of Rolls-Royce Phantoms that have been provided to the family since the 1950s. For more casual occasions like horse shows and polo competitions, Her Majesty sticks to Range Rovers and even a Jaguar estate wagon.

Armor all

Some leaders can't be bothered to take the wheel, while others -- like King Juan Carlos of Spain -- seek it out. He tools around in a Cote d'Azur blue Maybach personally loaned to him by DaimlerChrysler Chairman Dieter Zetsche. The rest of the Spanish royal family relies on a stable of top-end Audis.

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Across the pond, America's commander-in-chief is driven in an all-custom Cadillac DTS limo. The stretched supercar is customized by armored vehicle builders O'Gara, Hess, & Eisenhart, who have been beefing Presidential rides since the 1960s.

The base platform is a Cadillac DTS, but little of the original remains. For example, the flush-style door handles have been replaced by ones similar to the 1992-99 Buick LeSabre because their looped shape allows them to serve as handles for Secret Service agents running alongside the car. As the most heavily armored Presidential vehicle to date, it is reportedly able to withstand anti-tank grenade launchers and is also sealed against chemical and biological attacks.

Inside, the President disposes of a fold-away desktop for composing legacy-clinching correspondence. A secure communications panel ensures continuity of command and control, even on the road. For comfort's sake, the limo also features an extensive entertainment system and adaptive, massaging cushions.

Papal prerogative

And sometimes, even at the highest echelons of power, rides are still bummed. To much fanfare, Russia's President Vladimir Putin let President George W. Bush drive his 1956 Vega last year during a state visit.

Perhaps no customer is more prized than the pontiff himself, though. After Pope Benedict XVI came into office last spring, German auto companies such as BMW, Audi, and Volkswagen lined up to secure Vatican contracts to build the next Popemobile.

For the moment, Mercedes-Benz continues to supply the distinctive white pickup with a bullet-proof cabin based on its ML 430 series station sport-utility vehicle.

But BMW and Volvo have recently donated models for personal use by His Holiness. The Pope distributed these vehicles within Vatican City, and his official papal garage includes two black Mercedes sedans and a 1980 white Fiat Campagnola jeep.

Sultan of wheels

For sheer size, though, nothing can compare to the private car collection of Hassanal Bolkiah, also known as the Sultan of Brunei. At one time the richest man in the world, the Sultan sat on a fortune estimated at $40 billion, and he is said to have owned between 1,000 and 5,000 cars.

Although the number purchased by his business interests and the number actually used by himself and his family differ greatly, the Sultan personally owns 200 Rolls-Royces, according to the Guinness Book of World Records.

During the 1990s his family accounted for almost half of all Rolls-Royce purchases. His collection is also said to include unique conversions of Ferraris and Bentleys into station wagons, one-of-a-kind concept cars, and Formula One-style cars.

BusinessWeek.com took a look at some of the world's most recognizable leaders and some of their cars. Check them out here.