Back in 1962, GM boss Ed Cole ordered a prototype of a 4-seater Corvette and this photo shows that prototype back in the day.
"GM purchased a Ferrari with a 2+2 seating layout and brought it into the styling department to serve as inspiration for its new four-seat Vette. GM executive Bunkie Knudsen told the styling team that “ours should be slightly longer,” than the Ferrari, which would have made it better suited to ferrying around large American passengers." (Source: Corvette Fever)
"This photo shows the only four-seater C2 Corvette that was built in the studio at GM Design. There’s no proof this prototype was ever driven and it seems as though it was unable to move under its own power, with GM Design describing the vehicle as a “fiberglass model.” The vehicle was eventually crushed, so these photos (and some other black and white images that are floating around the web) are the only lasting evidence that it ever existed." (Source: GMAuthority.com)