Centro Stile and Zagato — the 'Il Mostro' Alfa Romeo, a fixed-production wedge-bodied 3.0 V6 coupe.
Built between 1989 and 1991 by Zagato in collaboration with Alfa Romeo's Centro Stile, the SZ (codename ES-30) combined the floorpan and 3.0-litre 75 V6 (210 bhp) with a fixed-production composite body. Production was capped at 1,036 coupes, all in red with a tan interior, with the open RZ following in 1992–1994.
The car is known internationally as 'Il Mostro' — the monster — for its blocky, slab-sided silhouette and triple-headlight nose.
Fixed-production, Zagato-built Alfa Romeo using one of the great Busso V6s; recognised collector status.
| Variant | Years | Production | Notes |
|---|---|---|---|
| SZ Coupe | 1989–1991 | 1,036 | Fixed-production coupe. |
| RZ Roadster | 1992–1994 | 278 | Convertible derivative; significantly rarer. |
Start with identity, paperwork and originality. For the Alfa Romeo SZ (ES-30), 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. Original paint, matching numbers, Alfa Romeo Historic / Italian register documentation.
Busso 3.0 V6 is robust; cambelt service is critical and should be no more than three years old regardless of mileage. 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.
Original chassis number from documented Italian or European delivery, untouched composite body and full Alfa Romeo Historic registration. 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.
Italian and UK Alfa Romeo specialists support the model; body panels are composite and require specialist repair. 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
SZ is firmly recognised as a collector Alfa and continues to firm slowly. RZ remains thin in supply with premiums to match.
| Date | Auction | Car | Mileage | Result |
|---|---|---|---|---|
| 2024-05-25 | RM Sotheby's Monaco | 1990 SZ Coupe | 32,000 km | €118,750 Sold |
Fixed production, Zagato build and Busso V6 underpin firm long-term demand.
Join Car Collector International's owners register for valuation updates, auction alerts and members-only events.
Register interest