Driver's wave
Race with an automatic and race with drivers view. Hold select down and the driver will wave.

Secret Car
In the first menu go to Single Race. Then go down to select track. Pick the Richmond track. Then go to select car. Press R2 two times then press L1 two times then L2 two times then press R1 two times then press R1 then L1. The Benny Parsons car will come up.

Track
Start a race at Charlotte. Then go five times around the finish line. A dirt track will appear in the infield.