SCOTTSDALE, Ariz. (AP) _ A 64-year-old car designed for royalty, a regal behemoth so exclusive that just six were made, is going on the auction block for the car lover who has more than a few million to spare.

The 1931 Bugatti Royale is expected to sell for a mere $15 million to $20 million at the annual Barret-Jackson Classic Car Auction.

The Bugatti Royale Type 41 Binder Coupe de Ville is 20 feet long and weighs 7,000 pounds. The body came down no assembly line, but from a carriage builder.

Bugattis, with their trademark horseshoe-shaped grills, were made from the 1920s to early 1940s by French auto perfectionist Ettore Bugatti.

The factory produced about 8,000 sports, touring and race cars that were flaunted by kings, capitalists and playboys, from King Leopold III of Belgium to the wine baron Philippe de Rothschild.

And among Bugattis, Royales were the ultimate, dubbed ``the car of kings'' by their maker.

The huge Royales, originally sold at a base price of $20,000 _ not including the custom body _ have appreciated considerably in value. In 1990, one reportedly sold for more than $14 million to a group of Japanese businessmen. One owned by Domino's Pizza founder Thomas Monaghan was sold for a reported $10 million.

The six Royales, built from 1927 to 1933, apparently have been brought together only once, in 1985 at the annual Pebble Beach Concours d'Elegance classic car competition at Pebble Beach, Calif.

The Royale entered in the Jan. 18-21 auction is the best of the six, said Chuck Rahn, a Scottsdale auto restorer. He called it ``art in its purest form.''

The auctioneers identified the owners only as Gen. and Mrs. William Lyons of Southern California.

The auction is expected to draw an international crowd of about 60,000.