Yes, some processes can be fully automated. No, we can not fully automate the assembly of a whole car. It’s still too complex.

One important caveat to this is that this isn't really a technical limitation, but more of a financial one. We absolutely could build a ridiculous Rube Goldberg machine of a factory that took raw materials in on end and spat out fully assembled cars on the other. And have it so automated that the place operates with the lights off.

However, it's far cheaper to build a mostly automated factory, rather than a completely automated one. It's a financial limitation, not a technical one.