Crash Team Racing Nitro-Fueled Puddle Hopper Trophy / Achievement Guide - Use the shortcut in Crash Cove.

After taking the first left turn (near start of race), there will be a small wooden ramp with a puddle of water behind it. Jump over the ramp for a jump-boost, drive through the puddle of water and in the last moment hold R1/RB for a high jump onto the meadow behind the water puddle. Using a character with high acceleration (such as Coco) makes it a bit easier. Alternatively, get a Turbo Boost Power-Up if you have trouble with this jump.