My thought on things thrown in...If the dealer/sales person throws it in, they could have come down more on the price instead, so you are still paying for it. Thrown in items are often not top quality, that you may have preferred. Don't ask will you take this much for it, but if you are ready, say I will pay this amount right now,(out the door price, no added fees) or I'm going to go look elsewhere. You can always go back, if they don't stop you, or call you.
If the dealer has a quality item you would like to purchase, after the deal is closed, you can likely purchase it at a reduced price at this time.
Jerry