In the early months of 1956 the range was expanded with the arrival of the BMW 300, which simply joined the 250, proposing itself with a 297 cm³ single-cylinder engine, with a power of 13 HP at 5200 rpm. In October of the same year, while in Italy the Iso Isetta was taken out of production, the BMW Isetta benefited from a significant update to the range: the Export versions appeared, destined for foreign markets, but also present in the German list. These versions were distinguished from the Standard ones primarily by the new roof and the new glazing, which on the whole appeared more similar to those of a normal car, while retaining considerable visibility. The windows of the Export became the sliding type, while those of the Standard version had only the opening in the two side deflectors. Other external differences were in the presence of chromed guides for the flow of rainwater and also in the presence of a bumper that embraced the entire front area in all its width. Mechanically, the Export versions were characterized by a significant revisitation of the suspension compartment: the front end benefited from the arrival of a longer swingarm, larger springs and new telescopic shock absorbers in place of the friction ones. The rear end became softer to promote internal comfort. The Export versions could be chosen with a 247 or 297 cm³ engine, as well as the Standard versions. In any case, the maximum speed of each model remained unchanged at 85 km / h. 
In 1957, however, the Standard versions were removed from production, leaving only the Export version in the price list, however available in both engines. Public acceptance, however, continued to remain high, at least for another year. Together with Goggomobil, the German Isettas continued to establish themselves as the most successful micro cars in the Teutonic market. But with the advent of the economic boom and conditions of greater general prosperity, the interest of the public began to shift more and more towards real cars. Thus it was that already by the end of that same 1957, the BMW 600 was also joined to the BMW 250 and 300, that is to say a sort of Isetta with an oversized body to accommodate four people, and finally, in 1959, the BMW 700. , a real small sedan, also destined for great commercial success. The Isetta continued to see its sales declining (from 40,000 units sold in 1957 to 22,000 the following year), but at the same time the demand for BMW 250 and 300 in assembly kits for foreign markets also increased. In short, although the BMW 600 and 700 were cannibalizing the sales of the Isetta, establishing themselves as new primary sources of income for BMW, even the small motocoupé (as it was called by the Germans) still represented a significant source of income for the German company. .
But in 1961 the BMW 250 and 300 turned out to be outdated and no longer appealing to customers: production went on like this until the following year, after which it was definitively ceased.