On August 2nd, RM Auctions will sell of a stunning selection of classic cars, including a coveted Mercedes-Benz Gullwing (above), at the annual Meadow Brook Concours d'Élegance in Michigan. The event takes place at Meadow Brook Hall, the historic 110-room Tudor Revival mansion built in the 1920s by auto heiress Matilda Dodge Wilson. In May, RM set a world record by selling the 1961 Ferrari formerly owned by James Coburn which we wrote about for $11 million.

The Mercedes, a beautiful black 1956 300SL, is estimated at $575,000 - $675,000. We prefer it to the other, slightly more expensive Mercedes on offer, a 1936 500K three-position drophead coupe by Corsica, est. $600,000 - $750,000. Also included in the stunning sale: a 1937 Bugatti Type 57 Ventoux Coupe, est. $475,000 - $575,000; a 1930 Isotta-Fraschini 8A Convertible Sedan by Castagna, similar to the one featured in Sunset Boulevard, est. $400,000 - $600,000; and a 1954 Jaguar XK 120SE Roadster, est. $80,000 - $110,000. See the gallery for more.

Renowned entrepreneur and broadcast veteran Art Astor is selling off part of his famous car collection in Anaheim, California this weekend. The sale, conducted by RM Auctions, mainly features American cars with a few classic imports of the kind we're partial to thrown in. We're particularly fond of this 1970 Jaguar XKE Series II Roadster, for example, which with an estimate of only $40,000 - $60,000 is something of a bargain. Also included in the sale: a 1927 Rolls-Royce Phantom I "Playboy" roadster which was used as a movie car and has been driven by Bette Davis and Robert Redford, est. $175,000 - $250,000; a 1968 Jaguar XKE Series I.5 2+2 Fixed Head Coupe, est. $30,000 - $40,000; a 1961 Jaguar XK150 3.8 Roadster, est. $80,000 - $120,000; a rare 1941 Chrysler Town & Country Nine-Passenger Estate "woody" wagon, est. $250,000 - $300,000; and a 1954 Chevrolet Corvette Roadster. est. $125,000 - $150,000. See the gallery for pix, and place your bids online at LiveAuctioneers.com.

The one-of-a-kind 1957 Chrysler Diablo concept car is unlike anything I've ever seen. It's a long sleek convertible which will be auctioned off at Monterey's famed classic car weekend this August by RM Auctions. The Diablo is one hot devil car, note the little pitchfork on the side . It was conceived by Chrysler's design head, Virgil Exner and built by Italian coachbuilder Ghia on a 1955 Chrysler 300 series chassis and Chysler invested over $250,000 in the project back then. It was a featured concept car for the 1957 US auto show circuit. At 22 feet in length this one must be a little difficult to take around corners. The car has been in the care of one owner for 25 years. It is estimated to sell for $2.5 to $3 million.

The ultra-rare Diablo will join several other European styled sports and racing cars and several classic American luxury automobiles at RM Auctions' Monterey auction "We have assembled the greatest collection of sports and classic cars ever brought together on the Monterey Peninsula," said Ian Kelleher, Managing Director of RM Auctions. "The Diablo is simply the holy grail of all concept cars in its era. Its upcoming auction in Monterey has received considerable international interest due to its rarity and the fact that concept cars are a featured highlight of this year's world famous Pebble Beach Concours d'Elegance," he added.

Admission to the Sports & Classics of Monterey is $40 per person and an auction catalog is available for an additional $100 including shipping and handling within North America.

Southern California is often heaven for vintage cars, no harsh weather to break them down and long straight roads for driving. On June 14, RM Auctions will present one of the great Southern California collections, the one belonging to the late Joe MacPherson. MacPherson was a passionate car enthusiast who spent his life devoted to buying, selling and restoring collectible automobiles which he kept at 'Joe's Garage' - a private automotive museum and banquet facility in Tustin, California. The auction will feature 50 historic motor cars for sale, in addition to selected memorabilia and a 25 outstanding motorcycles.

Highlights of the collection include the record-holding 1954 Chrisman Ford Bonneville Coupe, built by the famous Chrisman brothers; a 1957 McCluskey Sprint Car "Tamale Wagon", which won over 120 races and four California Racing Association championships; a 1966 Gurney Eagle Indy Car, which is considered amongst the most beautiful and inspiring of all Gurney Eagles ever built; and a multiple race-winning 1992 Chevrolet Lumina formerly owned by the legendary Dale Earnhardt. The big ticket of the auction is one of the most important Miller racing cars in existence, the supercharged 1923 Miller 122. Badged number 2, this example was driven by such racing greats as Eddie Hearne, Ira Vail, Earl Cooper and Bill Albertson. Following its retirement from racing and a full restoration, this car was awarded 'Best in Class' at the 2006 Pebble Beach Concours d'Elegance. It is estimated to sell fro $900,000 to $1.2 million.