What Ed Sheeran Can Tell Us About the Market for Classic Cars A notable exception last month was a 1956 Aston Martin DBR1 with a distinguished race history that sold for $22.55 million — an auction high for a British auto — at RM Sotheby’s annual bellwether series of classic car sales in Monterey, Calif. “The market is relatively stable, though some sectors are coming down,” said Brian Rabold, vice president of valuation services at Hagerty, a Michigan-based company that insures collector-grade cars. A 2004 Ferrari Enzo proved the most successful of the 71 lots at RM Sotheby’s, selling for 1.8 million pounds with fees, or about $2.3 million, to a telephone bidder, against a low estimate of £1.6 million. Forty-seven percent of the 71 cars didn’t sell, compared with a failure rate of 24 percent from 86 lots at the equivalent RM Sotheby’s auction in London last year. Mr. Hatlapa added that, unlike rare 1960s classics such as the Ferrari 250 GTO, which has been priced at as much as $55 million, they usually lack the allure of a race pedigree and depreciate steeply the more they are driven. “I don’t do it as an investment.” That said, since 2005, classic cars have generated the highest returns among so-called passion investments, with prices rising an average of 332 percent, more than two times the equivalent increases for watches, wine and jewelry, according to a Coutts index published this week.