Thunder Plates:
Select the Thunder Challenge or Lightning Challenge at the game mode screen.
Complete the various challenges to get new Thunder Plates. Note: The Plates
are awarded randomly from game to game -- winning a certain track with a
particular driver will not unlock the same Plate between games.

Night tracks and alternate tracks:
Race at the desired track in quick race mode under the veteran difficulty
setting. Win the race to unlock a night or alternate version of it.

Paint schemes:
To get all the paint schemes for all the drivers, race with the desired
driver. Select any track in quick race mode under the veteran difficulty
setting. Win the race to unlock one paint scheme. To get more, go to another
race track or the same one at a different time (for example, Bristol day or
night). This will not work if its the same time of day, such as the two
Richmond races or the two Loudon races.

Daytona: Easy win:
Make sure the race is set on ten percent difficulty. Then, cause a crash
on lap four. If done correctly, there should be a caution. Go into the
pits, and ignore that fact if no one else also enters. You will probably
be last, but there will soon be another caution and the leaders will come
in. Stay out and do not pit. After the stop, you should be in first or
second place. You will run low on gas, but you will not run out. Block and
you will be able to win.