The , also known as Ace, Viki, Sherpa, 500/600/700, Mini Jumbo, Mini Subaru or M60/M70/M80 in various export markets, is a kei class automobile produced from 1972 to 1992 mainly for sale in Japan by Subaru, although it was also sold in Europe, South America, Australia and the Caribbean. The Rex superseded the R-2 as Subaru's kei car, and has been available in commercial use versions as well as in a passenger car version. It underwent major changes in 1976, in fall 1981, and again in late 1986. The second generation Rex (1981–1986) also formed the basis for the larger Subaru Justy. The name "Rex" comes from the Latin word for "king". In some export markets, the Sambar microvan has been marketed as the "Rex Combi". The "Rex" nameplate has been reused since 2022 as a subcompact crossover SUV based on the A200 series Daihatsu Rocky. First generation The Rex (K21), introduced 15 July 1972, was the replacement for the Subaru R-2, which was itself the replacement for the long lived, but outdated Subaru 360. Because the R-2 was based largely on the 360, originally including its air-cooled two-stroke engine, it lasted for not even three years. In contrast, the 360 was produced for 11 years and the rear-engined Rex was produced for nine. The Subaru Rex represented a fresh start designwise, sharing little of its appearance with the Subaru 360, although they were mechanically the same and shared a rear-engine layout. The Rex also retained the 360/R-2's rear swing axle. The appearance of the new Rex was similar to Subaru's new compact car, the Leone. The Rex originally featured the same water-cooled 356 cc EK34 two-stroke engine as used in the R-2, and was available only as a two-door sedan. Outputs were . In February 1973 a four-door sedan was added. The Van was registerable as a commercial vehicle, allowing for considerable savings in taxes and fees. The EK34 engine came with a single carburetor on the Custom L, Super L, and other trim levels down to Standard, or a double carburetor for the sporty GSR. The TS (Touring Sport) received a iteration. The GSR was also somewhat lower than its counterparts, due to radial tires being fitted. In October 1973 the two-stroke was replaced by a 358 cc rear-mounted, watercooled, two-cylinder, four-stroke engine called the EK21. This produced at a peaky 8000 rpm and of torque at 6500