If you look at Pied Piper's page, they put it front and center that they serve independent dealerships. Tesla, on the other hand, has stated that they will never have independent dealerships. If Tesla wins, Pied Piper goes out of business. There is no way for them to be impartial. Most people, by the way, HATE car dealerships. That's why Tesla doesn't have any - they don't want your purchasing experience clouded by an asshole trying to make margin. I almost didn't buy a Honda for my wife because every Honda dealer I've ever met needs to die in a fire.
I don't think people want a dealership experience. Pied Piper PSI measures conversion, not vehicle sales. Your "satisfaction index" measures how well your dealership is doing vs. other dealerships, not how well one manufacturer's sales stack up against another manufacturer's. If you wanted to measure the contagion of a disease vector, PPPSI would be exactly the model to use. There are few classes of humans you can joke about freely anymore. Pedophiles, furries, car dealers. And some people feel bad picking on furries.