The Smart Steering feature in Mario Kart 8 will let players turn their Karts with some assistance but does not work entirely like an auto-pilot feature. This accessibility feature is hidden in the Kart setup menu but can activated before you finalize your Kart setup. The Smart Steering feature will guide you and prevent you from steering off-course. However, turning this feature on will put an antenna on the back of your Kart and flash a yellow color when activated.
