The add-on block — VIN etching, nitrogen fill, appearance packages, pre-loaded protection products — is where a clean deal grows $1,500. Practical protocol: request the buyer's order by email before you visit; reply declining each add-on line by name; bring the email. Pre-installed “mandatory” add-ons on used cars are a negotiation on the vehicle price wearing a costume. Stores that remove them without drama earn their paperwork-hygiene marks.