Yes. I know NUMMI. We did a field trip there once. It's an old GM factory from the 60s that transitioned to Toyota co-ownership because they needed to built cars in the US to get around import taxes and GM needed to get their employees, who (according to your link were) At the time of its closure "considered the worst workforce in the automobile industry in the United States". Still doesn't change the fact that when Tesla is the size of GM/Toyota etc, running tens of plants, I doubt any (besides maybe old NUMMI) will be based out of California.