Some of the greatest enthusiast cars in history have come from the fruitful minds of engineers forced to work in secret to avoid the swinging axe of the bean-counters or judgmental frowns of pragmatic executives. This was the case with the Mercedes-Benz 300 SEL 6.3 and its creator, Erich Waxenberger. In the mid-1960s, the Mercedes-Benz lineup was very conservative. Even the SL sports car was limited to six cylinders and heavily biased toward automatic transmissions and luxury touring. Mercedes' saloon car lineup was even more staid, with the W108 and its air-suspended sibling, the W109, topping out with a 3.0 liter, Bosch-injected inline six. Of course, these were wonderful cars built with exceptional attention to detail - they just lacked the performance that Waxenberger desired.