The Guppy's basic design is based on various Group 6 cars constructed by March Engineering for the Fuji Grand Champion Series; Mooncraft describes the vehicle as essentially a closed-body version of their MCS series of racing cars used in the Fuji Grand Champion Series.

The vehicle was developed using parts of previous Fuji Grand Champion Series cars that were no longer used to reduce cost;[2] the vehicle was advertised as "the world's cheapest Group C car".

[3] Two Guppies were entered: one driven by Toshio Suzuki and Toshio Motohashi and another driven by Taku Akaike and Yoshimi Katayama; they finished second and third respectively, behind Vern Schuppan and Naohiro Fujita's Trust Racing Porsche 956; this result equated to the Guppy scoring a class victory in its first race.

[7] By this stage, the Guppy was severely outdated with many teams having upgraded to Group C1 machinery.

Despite the vehicle's performance in later years, the Guppy was well-liked by privateer teams due to its good balance making it easy to drive.