I 'v set the illumination of the phone (T610) on automatic when it's in the
cradle.
This means that after some time the screen light goes down by 50% and the
keyboard light goes out totally. Waiting somewhat longer, and all the lights
go out.
But, when selecting the car profile manually and without putting it in the
cradle, the screen light won't go out, it will stay on at 50% brightness.
It will stay on all the time, even all night.

Sven