The Bill Thomas Cheetah was a sports car car built from 1963-1966 by Chevrolet performance tuner Bill Thomas as a competitor to Carroll Shelby's Cobra.

From Wikipedia. In the late 50's, Thomas had tremendous success racing Corvettes and he gained the attention of influential men within GM. By 1960, Thomas had started his own company and he continued his chain of successes by making other GM products such as the Corvair and Chevy II run circles around the competition. In 1963, Thomas used his connections to gain covert support from GM (through the head of its Performance Product Group, Vince Piggins) to develop a concept vehicle. The prototype was designed jointly by Thomas and his lead fabricator at the time, Don Edmunds. Edmunds is also credited with the bulk of the construction of the car. Financing for the project came from private investors including Thomas himself and John Grow, a Rialto, California Chevrolet dealer. In fact, the first car belonged to John Grow. Using his racing connections, Thomas arranged for material assistance from Chevrolet for the major components - specifically, the Corvette engine, transmission and rear-end assemblies.
Following delivery of the drive-train components, Edmunds laid them out on the shop floor and began taking measurements. With a few deft chalk lines on the floor, the basic outline of the chassis was determined. In fact, the original "blueprints" of the Cheetah consist of only a few simple drawings. This was Edmunds' trademark design methodology - sketch what he thought the car ought to look like, then build it. (The vast majority of the 600+ cars that Edmunds built in his career would be designed this way. Only his last few Indy cars would involve professional designers.) The bulk of the initial drawings show each major component drawn out in block form, with major dimensions marked. Given the basic chassis shape, Edmunds began sketching the body. Edmunds showed his drawings to Thomas and after a few minor changes, was given the green light to begin construction of what was originally meant to be a "Malt Shopper" - a cruising machine or styling exercise. Thomas wanted a prototype vehicle to show GM what level of work his company could do - all in the grand hope of winning additional contract work. Sometime after construction began, Thomas decided the car would also compete on the racetrack to further promote the concept. This midstream change in purpose was partly responsible for the chassis flexibility problems that emerged once the car began to compete on the racetrack.
Once Edmunds had the lower half of a rolling chassis built, he constructed a plywood body buck which fit on top of the chassis. The buck included removable metal frames which showed the outline of the windows. Once completed, the body buck and forms were sent off to California Metal Shapers and Aircraft Windshield Co. respectively. After the rough body arrived back at Thomas' shop, it was finished by Don Borth and Don Edmunds. A second car was also constructed with an aluminum body but the remainder of the cars were fiberglass. These fiberglass bodies were produced by two different companies - Contemporary Fiberglass and Fiberglass Trends. Note: It has been surmised by Thomas employees that the second aluminum car is the car that would eventually be sold to Chevrolet for evaluation purposes. It is also surmised that this is the same car that Thomas purchased back from Chevrolet to serve as a basis for the Super Cheetah, a project which, sadly, was never finished by Thomas. This car has recently re-surfaced and is owned by Robert Auxier.
The chassis was constructed of Drawn Over Mandrel (DOM) cro-moly tubing that was arc-welded. The design of the car was unusual in that it was front engined, but with the engine sitting so far back in the chassis that the output yoke of the transmission connected directly to the input yoke on the differential without an intervening driveshaft. With the engine positioned in this manner, the driver's legs were beside the engine. For this to work, the exhaust system headers passed over the top of the driver's and passenger's legs. The tops of the footboxes were curved to make room for Edmunds' handmade headers. This design takes the attributes of what is known as an FRM layout to an extreme. Consequently, this design gave a front/rear weight distribution roughly approximating a mid-engined vehicle without the cost of an expensive transaxle arrangement. Unfortunately, this design style also meant a very hot driver's compartment - an issue that would haunt the Cheetah on the track.