the first Supersonic clothed an Alfa Romeo 1900, tuned by Conrero and entered into the 1953 Mille Miglia. (Imagine that today - a coachbuilt sports car being commissioned for racing rather than concours trophies...)
The Supersonic design first appeared on a Conrero-tuned Alfa Romeo 1900, which was entered in the 1953 Mille Miglia. Designed by Giovanni Savonuzzi, it was crafted in metal by Ghia, which built eight examples on the 8V Fiat chassis.
The Supersonic body was also applied to three Jaguars XK120, an Aston Martin DB2/4 and an even more extreme version was built on a DeSoto Adventurer chassis. I didn't even see the connection, as the front of the DeSoto is so different
here is a Jaguar XK 120. Obviously, this did nothing to inspire the Ghia Supersonic look.
the Fiat Supersonic:
you can see the nearly identical body, without the bumpers