A dealership may attempt to deceive you in order to convince you to visit the dealership.
It gets worse.
If the sales manager believes that you were sufficiently gullible to have actually believed the deceptions intended to lure you to the dealership, you should expect that he or she will offer you the very worst terms.
If the owner of a dealership were pressed as to whether such tactics are ethical, he or she might answer that regardless of what lured you to the dealership, what matters is what you the customer signed your name to.
On that one account I would tend agree with the owner.