I’ve tried that bait and switch before, and it only caused conflict. It is not necessary to use that strategy. Oddly enough, they have no qualms lying, but they hate when others do it. Weird.In the past a good way to upset a dealer was pretend to get financing with them. At final transaction pull rug out and show them the local credit union offer with lower rate they can match or write deal over .
My preferred methods are to just pay in full upfront or finance with them, ensure there is no prepayment penalty and then refi after 30 days with my preferred lender. Less drama that way.