Porsche
928 GT “Flachbau” one-off

Why it matters

This 928 GT was ordered new in 1989 to its first owner's own specification and finished through Porsche Exclusive. Its defining feature is a flatter, covered pop-up headlight treatment in the style of the 944, replacing the exposed round lamps of the standard 928. The auction house describes it as a one-of-one car.

How rare is it?

Six separate kinds of rarity – never combined into one number.

Each kind of rarity is rated separately and never combined.

Production

Every figure says what it counts.

Independent counts (e.g. engine and colour) are never combined into a calculated figure. Surviving examples are never presented as original production.

History

The car was ordered in 1989 by its first owner, who customised it with Porsche's Exclusive department; factory codes 09981 and 09991 point to the special-wishes team. It stayed with that owner for almost 35 years and was serviced at Porsche centres and specialist workshops, according to the catalogue.

The odometer showed 56,636 km at cataloguing, but the original unit was replaced in 2003 and had recorded no more than 11,500 km at that point, so the true mileage is believed to be higher. Porsche Fahrer magazine ran a six-page feature on the car in August 2023, and RM Sotheby's offered it in Paris in 2024 without a sale.

Technical specifications

Engine

Transmission & drivetrain

Chassis, body & dimensions

Performance

“Not yet verified” means no source has been checked for that value yet. Nothing is estimated to fill a gap.

Sources

Each number links to the exact facts it supports.

1. 1
   Stuttcars – The Best Porsche Special Editions & One-Offs Level C

   • 1 one-off

   Accessed 2026-11-11
2. 2
   1989 Porsche 928 GT 'Flachbau' (Paris 2024, lot 129) Level C RM Sotheby's

   • one-of-one 928 'Flachbau'

   Accessed 2026-11-12
3. 3
   Time lapse: Porsche's transaxle models Level A Porsche Newsroom (Christophorus 418) · 2026-06-11

   • World premiere of the 928 with up to 176 kW (240 PS) V8 front engine
   • 928 GT with 243 kW (330 PS)

   Accessed 2026-11-12