The Ugliest Porsche 911 You Never Heard Of Is Also One Of The Most Valuable

It was modified by the famed Italian design house Pininfarina into a long-wheelbase, four-seat prototype, known as the B17. Listed on Hemmings by seller AutoClassica, this piece of Porsche history carries an asking price of $1,250,000.

Porsche's Most Psychedelic Sedan Came In The Late Sixties
The story begins in the late 1960s when Porsche commissioned Pininfarina to create a concept based on the contemporary S2 series 911 model. The brief was specific: develop a true 2+2 configuration capable of comfortably accommodating four passengers of average height.

Pininfarina’s solution involved significant structural modifications to a standard 1969 911 chassis (VIN #320020 according to the listing). The wheelbase was stretched by a considerable 7.5 inches to create adequate rear legroom, fitting a full rear seat reportedly featuring a wrap-around design. To provide headroom for those rear occupants, the roofline was correspondingly stretched and reshaped.

While the modifications achieved the goal of increased interior space, they came at a cost to both weight and aesthetics. The extra structure and materials needed for the stretch reportedly pushed the B17’s curb weight up towards 2,500 pounds, around 250 lbs heavier than a standard 911 of the era. This additional mass also shifted the weight distribution further rearward, to approximately 61 percent over the rear axle, potentially impacting the car's handling compared to its famously nimble siblings.

Visually, the results are undeniably unique, though perhaps challenging to Porsche purists. The lengthened roof slopes downwards towards the rear in a manner that some describe as awkward or "hunchback-like," drawing comparisons more readily to vehicles like the Chrysler Crossfire than a traditional 911 profile. The car currently wears an arresting shade of lime green paint, reportedly applied sometime during the 1980s. According to the Hemmings listing, Pininfarina originally delivered the car in a more conventional dark blue finish.

A Long-Hidden Piece Of Porsche History
This listing is the first time the unique B17 has ever been publicly offered for sale. It notes the vehicle has approximately 38,000 miles on the odometer and describes its current state as "good user condition." Specific details regarding the engine and transmission are limited in the listing, but presumably would mirror a 1969 911S base model. Photos show a black interior that appears largely standard, aside from the modified rear seating area.

While never intended for production, Pininfarina’s work on the B17 demonstrated the potential for adapting the 911 platform and reportedly influenced future Porsche design thinking. According to Hemmings, the exploration of design and engineering possibilities with the B17 later contributed to the creation of the 911 C20. That prototype, based on a 911SC, played a significant role in Porsche’s development of its all-wheel-drive systems.

This places the B17 not just as a curiosity, but as a notable step in Porsche's broader evolution. While its aesthetics may be debatable, its rarity and direct connection to both Porsche and Pininfarina history make it a significant collector's piece.