Visitors to the National Corvette Museum's 15th Anniversary Celebration are in for a real treat as General Motors will be loaning for display four Corvette Concept cars from its Heritage Collection. The four Corvettes to be displayed are the 1961 Mako Shark Concept, 1965 Manta Ray Concept, 1973 Aerovette Concept and the 1959 Stingray Racer.