Siren sign too high up and too small

[McGherkin]

The position is good IMO. Remember that everyone has a different setting for the view, and so some people may have their view of the road blocked if the symbol was lower.

As said before, it only gets bigger when police are near you. This is right too, since when they're far away you want to be notified but not as a matter of huge importance, and when they get nearer you need to pull over so the sign gets big enough to not be ignored.