Ambient lighting
To adjust the brightness of ambient lighting, it needs to be done from the on-board computer. Play with the buttons on the steering wheel and you should find "ambient light" under the "lighting" submenu. You can adjust from level 0 (off) to level 5 (bright). This is described in the operator's manual.
Not sure how bright you wish to have. Level 5 isn't that bright to me. But I guess that's why it's called ambient lighting.



