Some fees are set by law, but many dealer-imposed fees and add-ons are negotiable. The simplest strategy is to negotiate the out-the-door number, not each line item.
Sales tax (set by state/local law).
Title and registration fees (state fees).
Dealer add-ons (etching, protection packages, accessories).
Dealer markups listed on an addendum sticker.
Say: "I'm buying at $X out-the-door. If you can meet that number, we have a deal."
Let them rearrange internally. You only care about the total.
Optional add-ons you didn't request. If it's not tax/title/registration, ask why it's required.
It may be their policy, but you can still negotiate the vehicle price to keep the OTD total where you want it.