There was no factory in LA, the cars were shipped into the US via long beach harbor, and the US office was in Irvine, CA. I can't remember what that place is these days, but the building is still there.
apart from that, your history is pretty accurate. I used to own a DMC-12, back in the day. They're basicly sound cars, but like you said, they're underpowered. There is a place in Colorado that will install the Cadillac Northstar v-8 into a 'D', but the conversion costs $20k. That solves the power problem quite nicely.
