Driver to passenger in-car communication is one of the fastest ways to bring your driving skills to the next level. Even in a stock-exhaust vehicle, the wind noise at 100+ mph can interfere with your driver coach's instruction. We all have heard the joke about the V8 driver that misheard the coach's scream "Brake Brake Brake!" for "Great Great Great!" causing the driver to stay fully accelerated through the corner, scaring the heeby-jeebies our of the instructor. There's a reason for a driver communication system being one of the most common topics talked about in a group 1 meeting.