The Dome project, which translates from Japanese as "child's dream," was initiated by Minoru Hayashi in 1975. Hayashi sought to utilize expertise gained from auto racing to manufacture production sports cars. Design work on the Zero began in 1976 with the goal of creating a commercially viable vehicle that could finance the company's ambitions at the 24 Hours of Le Mans. The project was staffed by employees who largely shared professional backgrounds in the racing industry.
The initial Dome Zero prototype was completed in 1978. It featured a wedge-shaped exterior design influenced by the Lancia Stratos Zero, Lamborghini Countach, and Ferrari Berlinetta Boxer. Built on a chassis of square-section steel tube, the car utilized a rear mid-engine, rear-wheel-drive layout.
The vehicle was powered by a 2.8L Nissan L28E SOHC straight-six engine, the same unit found in the Datsun 280Z and 280ZX. This engine produced 143 hp (107 kW; 145 PS) and 23.0 kg⋅m of torque. Given the car's curb weight of 920 kg (2,028 lb), its performance characteristics matched those of Porsche models of the era. Technical specifications included a ZF 5-speed manual transmission, independent double-wishbone front suspension, and four-wheel disk brakes, with the rear units mounted inboard. To manage costs, Dome sourced several components from existing Japanese production cars, including the steering column from a Honda Accord, front brake calipers from a Subaru Leone, and interior door pulls from a Toyota Celica.
Following its exhibition at the 1978 Geneva Motor Show, the Zero attracted interest from investors, but Dome was unable to secure Japanese road certification. The company lacked the funds required to navigate the lengthy and expensive homologation procedures mandated by Japanese regulatory bodies at the time.
In response to the certification difficulties in Japan, Hayashi developed the Dome Zero P2 for the international market, specifically targeting the United States. Hayashi intended to sell the car abroad and then allow Japanese enthusiasts to acquire the vehicle through grey market re-imports, thereby bypassing local regulatory hurdles.
The P2 featured structural modifications and large front and rear bumpers to meet US requirements, which altered its visual profile compared to the original prototype. While it retained the Nissan L28E engine, contemporary press reports indicated that Dome was considering turbocharged straight-six engines from Nissan or Toyota for future production. The P2 was showcased at the 1979 Chicago and Los Angeles motor shows and received a positive review from Road & Track magazine. Estimated retail prices ranged from US$30,000 to US$60,000, but like its predecessor, the P2 failed to achieve homologation and never reached commercial sale.
The failure of the road car's homologation led Hayashi to focus on the Zero RL, a dedicated racing variant designed for the 24 Hours of Le Mans. The Zero RL differed significantly from the road prototypes, utilizing an aluminum twin-tube monocoque chassis and a Cosworth DFV V8 engine. Its design was characterized by a long 5.0-meter body and an unusually narrow track of 52.7 inches (1,340 mm).
The Zero RL made its competitive debut at the 1979 6 Hours of Silverstone. Driven by Chris Craft and Gordon Spice, the car qualified as the third-fastest in practice but finished the race in 12th place. Later that year, Dome entered two cars in the 1979 24 Hours of Le Mans. The #6 car was driven by Craft and Spice, while the #7 car was piloted by Tony Trimmer and Bob Evans; neither vehicle finished the race.
Dome continued its efforts at Le Mans with updated versions of the chassis. In 1980, the RL-80 was driven by Craft and Evans, and in 1981, the same pair drove the RL-81. Both entries resulted in retirements. Following the 1981 event, Dome concluded the Zero RL program, though the company remained active in other racing categories.
While the Dome Zero failed as a commercial venture, its appearance at the Geneva Motor Show generated significant revenue through licensing deals with toy manufacturers. These funds allowed Dome to expand its headquarters and continue the development of future automotive projects.
Engine: Nissan L28 straight-6, 2,753 cc
Power: 145 PS (107 kW; 143 hp)
Transmission: 5-speed manual
Weight: 920 kg (2,028 lb)
Suspension: Double wishbone (front), coils (rear)
Tyres: 185/60/VR13 (front), 255/55/VR14 (rear)