They are useless. The entire car buying process is a joke. Cars should be a set price and the only variable at play should be the financing rate due to different credit scores. It's 2019 and we have the internet, not encyclopedia Britannica. I've never met a car salesman that knew more than I did going in to buy a car, and I'm not saying that in an arrogant manner. Point is, the information is available. They serve no purpose but to harass and act like intermediary dope between you and the overweight finance guy. I don't need someone to tell me the car has 4 wheels and a rear view mirror.