Some cars leave a paper trail; the GM Z platform left a name and a place in GM (General Motors)'s list. What follows is what can be said with a source behind it.
Where it came from
The Z platform or Z-body automobile platform designation was used on three different types of vehicles made by General Motors.
In context
Nearby in the GM (General Motors) catalogue sit the 1955 Chevrolet and the 1957 Chevrolet.