A buddy's father by the name of Dr. Philip Lett was an American armored fighting vehicle engineer that lead the Chrysler Defense design team in the XM1 tank program, whose work resulted in the M1 Abrams tank currently in service with the U.S. Army. It was only after many years had passed when information was declassified and released into the public domain, that Chrysler's turbine car was used as a test bed for the Abrams powerplant, though there are significant differences between the eventual engine that first powered the Abrams, and the car(.....and that's why you test). Dr. Lett drove one for quite some time.
Dr. Lett was an internationally recognized consultant on defense technology, and was considered by most to be the world's leading expert on heavy armor vehicles. Dr. Lett served as the Vice President for Research and Engineering for General Dynamics Land Systems Division, and was Program Manager for the M1 Abrams main battle tank. Previously, he was General Manager of Chrysler Corporation's Sterling Defense Division, and prior to that, Chief Engineer for Chrysler.
When Dr. Lett passed, my bud was extremely surprised to find out his father was also CIA, and would receive full military honors at his burial.