I'm with you except the part where you say to "simply go in." I see no reason why I should go in. The aggravation of interacting with a dealer is not worth the pennies I might potentially save (but only potentially, and only if I do everything perfectly, and at the risk of losing my shirt if I mess up even slightly).

I want fixed price transactions. Dealers do not give this to me. Tesla does. Therefore, I go with Tesla. You don't have to. But you can't, and you shouldn't, advise me to do something that I plainly dislike doing. I have already made it clear that the money is not the issue, it is the principle behind the thing. Lack of fixed pricing is the precise thing that I find objectionable.

If a dealer, or anyone else, gives me a different price depending on my method of payment, then I am not going to be your customer. Full stop. I'm not going to try to game your pricing. I want to know that you are engaging in this practice, not so that I can exploit it, but so that I can avoid it.