Italian coachbuilder Castagna Milano has presented an unusually ambitious proposal for the Alfa Romeo Giulia Quadrifoglio: a two-seat convertible grand tourer with an entirely different body and altered proportions. The design attracted new coverage on October 21, 2026, but the distinction between proposal and production is essential. At present, it exists in renderings, and Castagna is looking for a customer willing to commission a single completed car.
The plan involves substantially more than removing the sedan's roof. Castagna wants to move the front seats 330 mm rearward, creating space for a dramatically longer bonnet. The bonnet itself would sit 40 mm lower than the standard car's. Rear doors and rear seats disappear, leaving a two-door, two-seat layout beneath a folding fabric roof.
The coachbuilder envisions an extensively reworked carbon-fiber exterior. Wider tracks and flared wheel arches give the proposed car a more planted stance. Its front end uses long fang-shaped daytime running lights alongside air channels for cooling, while the rear incorporates a diffuser, stacked exhaust outlets and an active spoiler. Castagna also claims the finished layout could provide 623 liters of luggage capacity even with the soft top stowed, an unusually generous target for a two-seat convertible.
The intended engine is the Giulia Quadrifoglio's 2.9-liter twin-turbocharged V6. The company also proposes a taller final-drive ratio to suit longer journeys. A target vehicle weight of approximately 1,420 kg has been circulated, but this should be understood as a projected figure rather than a measured specification from a completed car. No confirmed customer, delivered vehicle or final price has been reported.
The project revives an old connection between Castagna and Alfa Romeo. The Milanese coachbuilder produced special bodies for Alfa chassis during the marque's early decades, including work associated with the 6C and 8C era. The modern Giulia proposal would require major structural engineering, not simply a new exterior skin. That helps explain why the project depends on a bespoke commission rather than appearing as an official Alfa Romeo derivative.
If a buyer comes forward, the finished vehicle could become another distinctive coachbuilt interpretation of the Giulia, following the two-door SWB Zagato. For now, the striking images describe what Castagna intends to build, not what has already left its workshop.