At the starting line when the second light is dimming down press A.
Get Gold on all the cups on 150cc then at the end it should have the credits and pictures of some courses.Then reset the game and the title screen changed and then there's a option called extra and when you select it everything is reverse and the turns are flipped.
Submitted by: wazz wazz
Frappe Snowland Tip
Start the race and go around the course until you come to the bridge just before the start line. From the bridge jump directly onto the snow on the right from the bridge without touching the course on EXTRA go to the left. Go over the finish line still on snow and once passed the finish line quickly turn right and go straight left on extra. The flying dude will come and pick you up and take you back to the bridge except you'll now be on the next lap but it'll act as if you've already done that lap so you go straight forward over the finish line and you'll complete the second lap. Now you can jump from the bridge to the snow and do the same thing again to complete the third.
Submitted by Dylan Smith