The $6,000 profit per car referenced in the article is gross profit, not net profit. Net profit is considerably lower, around 5% for the mass manufacturers. So a $100 cost savings is very significant against a ~$3,000 net profit on a Bolt.
OP: ooooo, that's neat. Do you have a source? I struggled to find a source for even that $6,000 number.
The $6,000 number is a lot harder to calculate. The lower number is just vehicle profit from their investor reports divided by number of cars sold. The lower number is a lot more variable -- some years car companies lose money from their vehicle production side...