The Grand Prix was available as a coupe from its birth through 2002, and in 1990 a sedan version was added. The anomalous year was 1967, the only time a convertible version of the Grand Prix was produced. Despite its gorgeous, sweeping lines and vast open-air cruising deck, the Grand Prix convertible was not a hot commodity. The 5,856 convertibles Pontiac made that year were dwarfed by the 37,000-plus hardtop coupes that left the assembly line. You might think that rarity would have made the original base price of $3,813 for a convertible (about $36,000 today) a good investment, but you’d be wrong.
Of the 36 1967 convertibles that have hit the market in the last five years, only two have sold for above the $36,000 mark. The most valuable was a Hurst edition powered by a 455 cubic inch V8 that sold three times in the past ten years for an average of more than $100,000. More typical are the dozens that changed hands for between roughly $13,000 and $40,000. The most intriguing Grand Prix convertible in existence is a burgundy specimen that resides in the Smithsonian’s National Museum of American History, with a catalog number of 1999.0328.01. It was donated in 1999 by Siewchin Yong Sommer, who traveled with her husband Guenther to 49 states and 251 national parks over the course of 32 years, during which they put 150,000 miles on the car’s 428-inch V8.
