Also known as the Porsche 928-4 Four-seater prototype, this one-off 928 was created by the Porsche Development Centre in Weissach.

This was a version of the 928 S that was extended by 25 centimetres. The longer wheelbase and the modifications to the B-pillar and door frame meant that passengers in the rear had an extra 20 centimetres of legroom – attributes that can now be found in the new Panamera Sport Turismo in more or less the same form. Some additional features of this one-off creation were the projector headlights, hatchback design, leather interior and green tinted windows.

The car was presented to Ferry Porsche on September 19, 1984 as a gift on his birthday. It is now held by the Porsche Museum.