La Carrera Panamerica, by Pink Floyd, the documentary of 1992

this video was a good look at the 1990's running of the race, and it included clips from the 1950's and 60's to show the history of the race. It did a good job of explaining what brought the race to being, and how it's changed. One of the most unusual cars that has been in the race is the above, which I think is a Cadillac with an airplane greenhouse mated to the top instead of the cars windows, A and C pillars, and roof

it appears in the video at minute 56 and 50 seconds , and 57 and 10 seconds