I would wait till I see they had a lot of customers around then very loudly tell them how the rude manner in which they talked to you is the main reason you are going to buy from someone else but also make sure to mention that the other dealership is offering a better price! Pickle heads like that hate it when you let others know just what jerks they are and especially so when you do it in front of other potential customers. Who knows, you might save someone else some headaches as well.