The Porsche factory's flat-nose 935-inspired 911 Turbo — built in tiny numbers by the Sonderwunsch programme.
Built by Porsche's Sonderwunsch (Special Wishes) programme from approximately 1981 and offered as an official catalogue option from 1986, the Flachbau ('flat-nose' or 'slant-nose') 911 Turbo replaced the 930's signature headlamps with pop-up units in a 935-inspired flat front. Construction details and production numbers vary by source; widely cited estimates are 948 cars across coupe, Targa and Cabriolet bodystyles between 1981 and 1989.
The Flachbau is now the most sought-after factory derivative of the 930 generation and the bridge between the road car and the 935 racing programme.
Factory Sonderwunsch derivative built in genuine catalogue numbers; the most visually distinctive 930 and the closest road-car link to the 935.
| Variant | Years | Production | Notes |
|---|---|---|---|
| Flachbau Coupe | 1981–1989 | — | Most numerous body style. |
| Flachbau Targa | 1987–1989 | — | Open Targa derivative. |
| Flachbau Cabriolet | 1987–1989 | — | Open derivative. |
Start with identity, paperwork and originality. For the Porsche 911 Turbo Flachbau (930), the strongest cars have continuous ownership history, matching numbers where applicable, original books and tools, factory build documentation and evidence of work by manufacturer-approved specialists. Porsche Sonderwunsch / Werk 1 build documentation, certificate of authenticity, original colour and unmodified specification.
Mechanically a standard 3.3-litre 930 Turbo; turbo health, intercooler condition and cooling system integrity are decisive. A proper pre-purchase inspection includes cold-start behaviour, ECU diagnostics and fault-code history (where applicable), leak-down or compression testing, underbody photography, suspension and chassis inspection, brake condition and a long enough road test to expose heat-related faults. Deferred maintenance on a car of this class is almost always more expensive than buying a better-sorted example.
Use a paint-depth gauge, lift access and a specialist familiar with the model's factory panel gaps and finish standards. Collector value is dramatically affected by structural repairs, refinished panels, poor paintwork and missing factory trim or option content. Documented cosmetic refresh is acceptable; concealed accident or fire damage must be priced severely.
Factory Sonderwunsch cars with documentation lead. Period dealer or aftermarket conversions trade significantly below. Specification, colour, options and limited-build variants move values significantly. Buy the best-documented example in the most desirable specification you can justify, rather than a tired example of a rarer derivative that will need years of corrective work.
Regional ranges authored independently — each reflects its local market, not an FX conversion
Budget annually even if the car is used sparingly. Fluids age, tyres and date-coded rubber components must be replaced regardless of mileage, and stored cars need exercise. A documented maintenance rhythm protects both reliability and resale value.
Use a 930-experienced Porsche specialist for inspection; Porsche Classic factory programme supports certification. Before purchase, confirm parts availability for model-specific bodywork, electronics, gearbox and engine components. A discounted car waiting on unobtainable parts or a factory service slot is rarely a saving in collector ownership.
Each region quoted in its local currency — independent market readings, not FX conversions
Flachbau values have firmed materially as the air-cooled Turbo market has matured. Porsche Classic certification has become the decisive market signal; undocumented or converted cars trade at a meaningful discount.
| Date | Auction | Car | Mileage | Result |
|---|---|---|---|---|
| 2025-08-15 | Gooding & Co. Pebble Beach | 1989 911 Turbo Flachbau Coupe | 18,000 mi | $489,500 Sold |
| 2024-12-04 | RM Sotheby's Miami | 1988 911 Turbo Flachbau Targa | 22,000 mi | $561,000 Sold |
Closed-production factory Sonderwunsch 930 derivative. Documented factory cars with Porsche Classic certification should continue to lead.
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