I am still getting small bits and pieces of information on the Nikon Z8 camera. The latest rumors suggest that the Nikon Z8 camera body or parts will be made out of high-stiffness carbon fibre reinforced thermoplastics or a similar material. For comparison, the Nikon Z9 has a magnesium alloy body.
Nikon has used carbon fibre reinforced thermoplastics in the past:
According to Nikon’s website, the D780, D5600, D5500 and D3400 cameras all used high-stiffness carbon fiber reinforced thermoplastic (click for larger view):