From Carmax | Buying A Car

: You can return the car within 10 days or 750 miles for a full refund if it isn't the right fit.

: Includes a 90-day/4,000-mile limited warranty (varies slightly by state). buying a car from carmax

: An optional extended service plan that covers major systems for up to several years. What You'll Need to Bring : You can return the car within 10