Can be used in conjunction with Smart Steering, essentially you don't have to hold down the accelerate button

The antenna blinks when Smart Steering is active.6

If you want to turn off Smart Steering, Auto-Accelerate and the like, pause after a race has started and the top corners of the screen should show you how to toggle these.

If the Smart Steering mode is on, the player's vehicle will have an antenna sticking out its rear end