Daihatsu has had a long-running development program for electric vehicles, beginning with the production of "pavilion cars" for the 1970 Osaka World Expo and continuing with the production of golf carts and vehicles for institutional use, such as the DBC-1. An electric version of the company's Fellow Max kei car also followed, the beginning of a series of prototypes. The 1973 oil crisis provided further impetus and at the 20th Tokyo Motor Show (1973) Daihatsu displayed a 550 W electric trike (TR-503E), the BCX-III electric car prototype and daihatsu's own EV1. Daihatsu showed more prototypes through the 1970s, for instance at the 1979 Sydney Motor Show, and then joined the Japanese Electric Vehicle Association's PREET program (Public Rent and Electronic Towncar) with an electric version of the Max Cuore kei car. The program allowed registered users access to the cars with a magnetized card and charged according to mileage used.