Making a display brighter?

[Navigator]

Hi guys,

Using the RSS FH 2023 and the custom display from Schmwalik (the older version with the whole screen going white when using brake-balance, I love that one) it is pretty dark.
The new screen/display from the same maker, is better, but I love the older one.
Since the new screen/display is a totally different setup, I can't reverse-engineer.

For it to be properly visible, I had to take out the glass component.
Now the thing is, when the sun comes from the back, shining right into the display, the numbers (and bars and stuff) are bright enough.
When sun is in your face, the display is very dark.

I played around with brightness and reflections: nothing helped and since it is an RSS mod, I can not open the steering wheel kn5.

Does anyone have a suggestion as to what I can try next?