The Reverb is Stanford's vehicle, part sports car, part advanced sound system.
It's main function is its sound based abilities. It can fire sonic pulses from the rear, sides, and below the car for different techniques and can be used to echo-map Battle Zones for finding enemies and Battle Keys. Underwater, it functions similar to a sonar system. Its main weapon is a pair of cannons in the hood that fire sound blasts. In the episode "Shadow Runners", the Reverb's computer is able to interpret Morse code.
This vehicle is used for the combination SonicSlash, where the sound and cannons of the Reverb are merged with the Saber's blades.
If you look on the bottom of the 1:64 scale model (shown above) you can kind of see the British Flag (Stanford is British too.)
At first Stanford as trouble naming the Reverb starting with the Boomer then the Pulsator before choosing Reverb