Just picked up a 2015 sGT. It has the automatic on/off headlights. The settings options are High, Med High, Medium, Med Low, and Low. The manual does a poor job of explaining what these settings are. It says "The headlight illumination on/off timing based on surrounding lightness/darkness". Does HIGH mean that the lights will only come on when it's darkest, or is this highest sensitivity so it will come on when it's just slightly dark?