Beach Buggy Racing 2: Island Adventure (EP)

To do the stunt challenges you need to collect the medallion from each track, but they only appear on 1000HP. There will usually be a ramp somewhere off the main track to help you reach the medallion.

From the main menu I chose "Race" and changed speed to 1000HP. I turned off all power-ups except Boost Juice (press at the track selection screen to edit rules) . It works great if you need some extra speed or if you undershoot, it can help you get that last little bit of power to reach the medallion.

Lastly, pay attention at the scenes at the beginning of the race. You can spot the location of a few medallions this way.