Porsche has thrown open a Web site registry at www.porsche60years.com to find out. Called My Classic Porsche Search, the program is intended to find and document the oldest of the brand’s models in the United States as part of the company’s celebration of its 60th anniversary in the United States.

Owners in 12 model ranges--including the Porsche 356, the 911, the 912, the 914, the 924, the 928, the 944, the 968, the Boxster, the Cayenne, the Carrera GT and the Cayman are encouraged to enter their cars. In addition to finding the oldest Porsches in each model range, the search will identify the oldest Porsche ever sold in the United States. The search ends Oct. 1.

The oldest Porsches and their owners will receive special recognition and become eligible for additional awards, including an exclusive badge from the Porsche Museum in Stuttgart. Images of some winning models will be featured at the new “Sixty Years of Porsche in America” exhibit, opening on Oct. 12 at the Porsche Museum, and one car might be selected for display at the Porsche stand during the 2010 Los Angeles Auto Show this fall.

All entries will be evaluated for authenticity by a Porsche panel of experts, including experts from the Porsche Club of America.

Porsche also will launch a national My Porsche Passion Contest on Aug. 24, giving Porschephiles an opportunity to write and upload up to 500 words on their unique Porsche passion for a specific Porsche car. The contest ends on Nov. 1, when 20 winners will be chosen for an online contest. The top three winners will get an all-expense-paid trip the Porsche Sport Driving School in Birmingham, Alabama.