“Payment Packing” is when a car dealer quotes you an inflated monthly payment. Dealers refer to the practice as "getting a little leg."
Example: If your actual payment on a loan is $300 per month for 60 months, the dealer might get you to agree to pay $350 per month. The difference in the actual payment and the payment you agreed to is called “leg.” After you agree to the inflated payment, the finance and warranty salesperson will tell you that he can add a warranty, or GAP, or other products, and keep your payment the same. Your real payment is much lower, and the warranty and other products are increasing it. Beware if a dealer offers you products or services “for free.” Chances are, you are paying for it.
You can protect yourself by keeping a copy of all paperwork presented to you. Or, use your phone to take a picture of terms and conditions offered to you.