In looking around, AFAIK this was the very first model kit of the Chaparral 2. I had one as a kid in the 60s, later in the 80s when collecting, and another one acquired recently.
The previous Hawk kits of the car were made of a pure white fairly rigid plastic (styrene) about 1/16" in thickness (per my memory). The one I have now is a rather semi-flexible translucent ivory plastic that is less than 1mm in thickness and weighs barely 10gms.