I finally pieced together the story on Ab Jenkins and Alex Tremulis' 1946 "American Meteor" land speed record car designed to bring the record back to the United States. It appears that even the great Ab Jenkins had trouble getting sponsorship for such a car, in this case a jet-powered rocket-assisted 600mph projectile based on the P-80 fuselage from 1944. The full story is at:
http://www.gyronautx1.com/live-updates but here's a couple photos and descriptions in the mean time...