Reach Level 16 to unlock the All-Star Race. Reach Level 18 to unlock the Bud Shootout.
Unlock All Cameos
Select the Features option on the main menu, then Create-a-Car. Enter the name Seymore Cameos as printed.
Unlock Cameos
To unlock all Cameos, create a car in the Features menu. Name it "Seymore Cameos" to unlock the bonus.
Dale Earnhardt Bonus
Win the Daytona 500 in season mode driving Kevin Harvick's #29 car to unlock Dale Earnhardt. You will also get the Goodwrench car, Goodwrench Plus car, Wrangler car, Silver car, Coke car, Bass Pro Shops car, Oreo car, and the Legacy car.
Unlock All Create-a-Car Sponsors
To unlock all create-a-car sponsors, win the Winston Cup in Career Mode and you'll get a thunder plate that states all create-a-car sponsors are unlocked.
Unlock All Dale Earnhardt Cars
Beat every rookie lightning challenge to get all the Dale Earnhardt cars.
Unlock All Fantasy Drivers
Go to create a car and put in for your first name as extra and your last name as drivers.
Unlock All Normal Driver Special Paint Schemes
Win 5 Championships and you'll get all special and retro Winston Cup paint schemes.
Unlock Fantasy Drivers
To unlock the fantasy drivers, just win three championships in career mode.
Unlock Kitt Paint
To unlock Kitt Paint, win the Winston Cup in Career Mode.
Unlock Paint Schemes for Other Drivers
Win a race in Veteran Difficulty to unlock a different paint scheme for your driver.
EA Sports Bio Bonuses
If you only have Nascar Thunder 2004:
Reach EA Bio level 16 to unlock the All-Star race at Lowe's
Reach EA Bio level 18 to unlock the Bud Shootout at Daytona
If you have Nascar Thunder 2004 AND Madden NFL 2004 saved games:
Reach EA Bio level 10 to unlock the All-Star race
Reach EA Bio level 12 to unlock the Bud Shootout
Driving locked cars
In multi player mode, you can drive a locked car. This only works with one person at a time. Have a player choose their car, then have the other player go to the same car. It changes to a locked car. After that, they can choose their car.
The Perfect Car
Reach level 28 in your EA Sports Bio and you will unlock the pace car, Buster Auton. The pace car will not receive any damage when it is hit.