Invisibility is used in Crash Team Racing, Crash Bandicoot: The Wrath of Cortex, and Crash Nitro Kart. In CTR, this is only used for battle mode. The aim in using Invisibility is to be not seen by opponents during a race and even Tracking Missiles, Red Eye Missiles, and Homing Missiles can't see players without indication of an opponent's target. However, just because players can't be seen doesn't mean they cannot be hit.
In CTR, when juiced up the invisibility lasts slightly longer.
In CNK, this is used for stealing flags and sneak attacks. Also, players will see a shadow of the invisible character.