Every buyer has stared at a purchase order and wondered what half the line items actually mean. Some are legitimate. Some are pure margin. Here's how to tell the difference.
Documentation fee ("doc fee")
A charge for preparing paperwork. It varies wildly by state — some cap it, most don't. It's negotiable more often than dealers admit.
Dealer preparation / lot fees
Charges for cleaning, fueling, and prepping the car. In most cases this is already covered by the manufacturer. You can usually get these waived or reduced.
Add-on products
VIN etching, paint sealant, nitrogen tires, appearance packages, aftermarket alarms. These can add $1,500–$3,000 with almost no real value. You can decline them.
Extended service contracts and GAP
These can be worthwhile — but the dealer's version is often 2–3x the price you can get through your credit union or an independent provider. Never buy them the same day; take 24 hours to shop.
Interest-rate markup
The lender approves you at one rate; the dealer can add up to 2 points on top and keep the difference. Always ask for the "buy rate" and compare to at least one outside pre-approval.
Trade-in undervaluation
Your trade-in is a separate negotiation. Get an independent value before you sit down.
The short version: read every line, and don't be afraid to say no. Or hire a service that does it for you.