The magnum opus on Porsche: Excellence was expected, by Karl Ludvigsen gives a bit more, including a pic of BB-PW989, according to Bez to the Learjey for the Road.
There were tow competing designs, one by Giugiaro and one by Harm Lagaay, who had just taken over the styling department. His was the design of the car shown. Bez: Piech and I spent half an hour in the studio alone with a model of Lagaay's design and could not find enything wrong with it.
The new engine was a 3.6 all-alloy V8, DOHC, weighing 419 pounds
engine size could be stretched to 4200 cc, giving 344 in stead of 300 BHP (after the 989 was axed Porsche tried to sell the engine to others, but nobody wanted it).
Development of the car was done by using a Mercedes 300CE body fitted with engine, powertrain and suspension of the 989.
The cancellation of the project in January 1992 was mainly based on the horrendous cost overrun already experienced and the uncertain market chances of the car.
Ludvigsen does not mention whether the prototype still exists, but he quotes Wiedeking: We tried to something of the project (i.e. selling the engines) but we failed so we scrapped everything.
Whether he meant this literally is unclear.
What was certain is that the project created a lot of antagonism within Porsche, with blames mostly going to Bez and Arno Bohn, who became Porsche MD in March 1990.
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