Here is a picture of the X-215, turbo powered, topless, concept car that they showed in the Detroit Car Show in 1962.  Read more about this car in Jim Noel’s bio.

{gallery}X215ConceptCar{/gallery}

This is the J-TR – a 1963 Concept Car.  It too was built on a convertible platform.  Note the exhaust port built into the rocker panel and the impressive interior.  No side chrome!  Great tail lights!

{gallery}JTRConceptCar{/gallery}

Pictures used with permission from: General Motors LLC