Used Cars was the one that had the scene where the sales guy placed a large rock under a tire during a test drive and backed over it. He had a trained dog scoot under the car and play dead, making the customers feel guilty enough to buy the car telling them this was the dog’s favorite car (or something like that).
You killed my dog, mister. You killed my dog! All he wanted was for you to be happy in this car
and now hes dead.