Why dirty cars cost more at the Pebble Beach auctions

The most-sought after accessory to any vehicle for sale in this year's Pebble Beach car frenzy isn't mechanical or even man-made. It's dirt — namely a natural layer gathered over a minimum of a decade as a vehicle moldered away as some forgotten family heirloom. In the strange world of rare vehicles, even neglect becomes a valuable commodity.

The cult of the "barn find" has grown to such a state that it's no longer sufficient to just say a vehicle emerged from an old shed. Washing the dirt off a stored car takes away a piece of evidence that's increasingly valuable to collectors; without that dirt, it's easier to raise doubts about what kind of repairs or botched restorations might have been attempted in the past.

At the RM Auctions on Friday, a 1965 Shelby 289 Cobra that had sat since 1987 was offered just as the seller had acquired it from the previous owner's estate, with dirty tires, trunk and engine compartment. It sold for $720,000 Friday night.

An even better example will be one of the centerpieces at this weekend's Goodling auction. This V-12 powered 1965 Ferrari 275 was imported to the United States in 1969, where its owner, an Illinois doctor, drove it a bit, then parked it with about 35,000 miles on the odometer. He kept getting license plates for it until 1974, then gave up.

Fast forward to this May, when a Ferrari collector who'd heard of a long-forgotten Ferrari in Illinois convinced the doctor to give him a look. The car sat as it had been parked nearly 40 years ago — with license plates, old Allstate insurance tag, even the period-correct pushbutton AM-FM radio. More importantly, the car had never undergone major repairs, and all its internal parts and bodywork were original -- including the headlamp covers concealing a thick mat of plains dust.

The collector bought it on first sight, and Goodling has been careful to preserve the patina of dirt on the exterior that just begs to have "wash me" written on it. The Ferrari's expected to fetch between $850,000 and $1 million — with the new owner getting not just a rare Ferrari that hasn't been driven since the Nixon administration, but the privilege of providing its first bath of the 21st century.