Whoever is interested in this should take a look at Netflix' "Dirty Money" Episode 1. Alex Gibney (also directed Enron - smartest guys in the room) gives a good overview of the scandal, if you haven't been following it closely on the news. Very interesting, although I would have appreciated a deep dive into the actual algorithms used.. I'm sure there's articles on this though..

Regarding the human tests, as scandalous at it sounds on first glance, the SWR & ARD (government funded news channels similar to the BBC) also reported that it apparently isn't unusual to do this kind of human testing. The subjects were exposed to one specific kind of gas, and the dose, according to their correspondent, was less than what someone living at a busy street consumes regularly.

He mentioned that even Greenpeace "knows of these studies", referring to them in one of their papers.., whatever that means exactly.. He also states that the scientists were openly communicating that they were funded by the car manufacturers.

https://www.swr.de/swraktuell/bw/neben-affen-auch-menschenve... (google translate should do a good job if you don't understand German..)