Im not necessarily fond of 50s cars but these 2 are just awesome

The packard predictor: the packard predictor is the last car made by packard, never made it to production which sucks, but we got one hell of a concept car out of it.

the oldsmobile delta 88. This one actually did make it to production, and actually paved the way for later muscle cars like the camaro, and charger

We owe it to the delta