The drop tank used to make the car is a Douglas Mk.8-series 300-gallon tank, which had applications to post-WWII Douglas aircraft, such as Skyraiders. There were a few different versions of the tank, some with tail fins. Here is another of the exact same type:
http://www.forgottenfield.com/amg/fuel/And another:
https://www.instagram.com/p/uYlpKDL_WZ/Here is a photo showing a Skyraider with these 300-gallon tanks installed (which I originally found mistakenly labeled as the smaller 150-gallon type). In order to carry these, the hardpoints had to support 2,000 lbs., rather than just the 1,000 lbs. of the 150-gallon tanks, and therefore I believe were not suited for Corsairs.
The tank fitted to the Corsair in Joe's post, although similar in design, is only half the size at 150-gallons (too small to make a belly tank racer out of, at least for a grown person).
This first picture is of the exact same 150-gallon tank as fitted to the Corsair in Joe's post (the Collings Foundation F4U-5) - similar design, but only half the size, and numerous detail differences. It could be and was used on a number of different aircraft:
http://www.angelfire.com/art2/dashvii/i ... optank.JPGAnd more photos of the late WWII/post-WWII 150-gallon tank:
viewtopic.php?p=382152If it is hard to see the difference in size between the 150-gallon and 300-gallon tanks, just look at the difference in the proportion of the size of the fuel cap compared to the size of the tank, and the slightly different locations of the fuel caps.