Turbo Start: When 'Go' appears at the start of a race press the Left shoulder button.
Unlock 3 Bonus Beetles Successfully complete ALL of the Novice tracks to unlock 3 new cars.
Unlock Police Beetle: Complete ALL the standard Championships and unlock a bonus mode. Then hold C-Left while driving the Police Beetle to turn on the siren which will make the other racers slow down and stop.
Alien Beetle: Complete the Professional Championship.
Unlock 6 New Beetle Battle Arenas Apart from the 3 Beetle Battle arenas you begin with there are 6 more that are unlocked by playing in Championship mode and collecting ALL 100 points worth of boxes on a course in one race.
Unlock Pyramids Arena: Collect ALL the point boxes in Sunset Sands
Unlock Woods Arena: Collect ALL the point boxes in Wicked Woods
Unlock Rooftop Arena: Collect ALL the point boxes in Metro Madness
Unlock Castle Arena: Collect ALL the point boxes in Coventry Cove
Unlock Iceberg Arena: Collect ALL the point boxes in Mount Mayhem
Unlock Volcano Arena: Collect ALL the point boxes in Inferno Isle
Start in one player championship mode on the Coventry Cove track. You then need to take a shortcut which is located near the barn with 2 haystacks. Then drive through the haystack which is closest to the track and hit the Daisy Box inside. You should then get a "Groovy" notification that you have done this part correctly. Once you have finished the race a cheat menu will be available at the options screen.