[rcweingart]

Because some people want roll up windows, heater/aircondonditiong, power steering, power brakes, windshield wipers, finished interior, etc. In other words, a street driveable "finished" automobile instead of a racer/kit car. If one were interested in primarily a track car, then Highland, FFR, Shell Valley and the like are all good options but no-one other than Superformance offers a "finished" street car - one that even has a semblence of pedigree, vis a vis, Peter Brock and Bob Negsted. And, if looking for pedigree of sorts, then a McClusky on a CSX chassis, especially a real roadster chassis.