What should I avoid in the finance (F&I) office?

Don't buy products in the box. GAP, service contracts, theft etch, and key replacement are pitched in a high-pressure session designed to add thousands after you've already mentally bought the car. Some of these are worth owning — at the right price. Most are marked up two to four times.

Tell the F&I manager you'll think about it. They can sell you the same products later, or you can decline entirely. And never fill out a credit app before you have the OTD price in writing.