8. Don’t buy the same day you test drive a car.

Salespeople know you’ll be excited after a test drive and that you’ll quickly want to take home a shiny, new and fun car. That’s why they want you to come back inside the dealership and “talk numbers” immediately after the joy ride, Shattuck says.

They’re counting on the impulse buy and that you won’t be prepared. Don’t fall for it, and walk away after the test drive, she recommends. Buying a car is a process, not an event, Shattuck says.