Some will see the tonneau cover as something pretty trivial. Is it?
In this Munro Live video you get to see what makes the Cybertruck tonneau work and see it compared to the Rivian one.
While it would seem that there would be little difference between tonneau covers, that is not the case. In particular, the Cybertruck cover rolls up. The Rivian version is more like a cartridge. No matter how it is made, materials choices is important. This is a big consideration as this is a mechanical system that clearly could experience a lot of wear.
What you will learn is that there are compromises in the design and, at least for me, they were more significant than I expected.