i also read an old article about how the 300e came to be.
apparently, a number of Benz engineers needed to get a message across to their management, and they did it this way: They told management that they had an experimental engine in one of the Benz test cars and invited them to drive the car, on the condition that they do not open the hood.
the engine proved very smooth, tractable and powerful, and the managers came away from the test drives positively impressed. They now demanded to know what engine modifications the engineers had introduced, and the engineers obliged.
They opened the hood to reveal ... a BMW inline-6 engine.