I just got a Varia RTL510 and paired it with my Edge 830. I noticed that when cars are approaching, the left and right sides of the display are shaded. When the cars pass, the shading goes away. See the screenshot below:
What this the purpose of this shading? It obscures the display and wastes real estate on the screen. The moving dots are enough for me to know that cars are behind me -- I don't need this shading also. Is it possible to disable this?