to be fair, the car in question was the FIRST prototype.
Later models were apparently still referred to as prototypes as they only made about seven vehicles and each appeared to be a bit different.
in order below are the rear view of the first production vehicle (still probably prototype), then #2 build and then the final version that was about to be sent out to a dealer.
Note that all the vehicles bear the same plate except for the last one.
I would post the author and book that these are from but don't know if it is allowed since *several* recent puzzles appear to be from it.