Bob, the cool thing about the Aerotrain is that it toured many of the railroads across the country and did regular service on the Pennsy, UP, NYC, Rock Island, and Santa Fe for periods of time between 1956 and 1960. It was a disaster for GM, which tried to use standard bus bodies for passenger cars, but it went right along with the era when it came to styling. Looking back from our vantage point of 50 years, the Aerotrain looks pretty silly, but I remember thinking, as a kid, that it looked pretty neat. The rumor I've always heard is that the designer of the 1957 Caddy was also the guy that designed the Aerotrain nose.