What a great birthday gift.

Porsche made just one 911 Speedster during the 993-generation's production run. The automaker gave it to Ferdinand Alexander "Butzi" Porsche as a 60th birthday present. Since Butzi had a leading role in designing the 911, it only made sense to give him a unique one in recognition of what he did for his family's company.

Butzi also designed the Porsche 904 race car. He left the automaker in 1972 to found the Porsche Design Studio where he designed things like watches and sunglasses.

Gallery: Porsche 911 Speedster History

Butzi's 911 Speedster is in the colour Aventurine Green, which is a deep, forest-like shade. The interior has chocolatey, dark brown leather upholstery, and wood trim adorns the lower part of the dashboard. The seats come out of the 911 RS.

There's a four-speed Tiptronic gearbox. While this probably wouldn't be the enthusiast's choice, for a person getting on in years like Butzi at the time, the automatic makes for easier motoring.

To create the one-off vehicle, the Porsche team took a 993 convertible and then fitted the windscreen and tonneau cover from a 964-gen 911 Speedster. The engine is the stock 3.6-litre flat-six air-cooled from a Tiptronic-equipped Carrera that makes 282 bhp (210 kilowatts or 285 metric horsepower).

Butzi Porsche didn't drive his bespoke 911 Speedster very much. Currently, the odometer shows just 2,085 kilometres (1,296 miles). The car is now part of the Porsche family collection, so even seeing it is a special opportunity.

It's worth noting that there is a second 993-gen 911 Speedster from the company, but this one came later. The car belonged to Jerry Seinfeld and started as a convertible. In the late 90s, he sent the vehicle to Porsche Exclusive for the conversion. There were some differences from Butzi's, like having the broader wings/fenders from the widebody layout.