Thanks dhn, for your answer...
Frustrating though, that they didn't consider the effect on night driving.
This is combined with the fact that the night brightness does not reduce enough for dark driving conditions. It's bonkers really. Only workaround I know is to cover the screen with darkened green or red plastic at night. It's hard to believe the TT folks failed to consider this.
Also, to me, the bottom panel of information on my XXL 540 is very poorly done - it takes a lot of space, displays things I don't want or need, and does it illogically.
For example, The number for predicted amount of Time to arrival should be over predicted clock time of arrival.
The destination symbol should be over the distance to destination.
Putting these things diagonal to each other is maddening.
Not everyone wants speed displayed on the gps. I have that already on my dashboard. I also already have a real time clock on the dashboard. It wastes screen real estate to put them on the gps.