CACHE IS NOT AT THE POSTED COORDS!!
The First Key challenge in the movie is a race Once the player has decoded the clue, they must drive ? at full speed at the start of the race. Near the wall at the back of the race, an entrance to an underground tunnel will open and the player can drive safely through it backwards beneath all of the obstacles of the race to emerge beyond King Kong near the finish line.
They must drive what at full speed?
Certitude