Simple graphic thing, but very important in my opinion
Probably it is not a good place, but I am not sure how to make a new topic (cant find a button, am I too stupid or blind?). I read a lot about historic or less historic air wars and quite often, enemy detection became from spotting this small detail which is a canopy or metal parts glowing - reflected by sun. This effects works stronger from larger distances where reflected beams seem to be cumulated, most of games includes of course proper lighting model, but without this effect. (it is also useful during close dogfight when we seek an enemy plane "camouflaged" below by the terrain downthere). This short spark can help much in such a situation. The other thing is that lot of building's roofs have also the same tendency - from larger distance any town is never totally matte, there are strong, almost mirror effect reflections on some roofs.
I do not think it is hard-to-make effect for graphicians (and not consuming additional power) - the only game I've seen this small but strong glow was ... GTA vice city where similar glows were showing up on cars' windows while watching at proper angles against the sun. It was probably a simple masked additive glowing and very rapidly blinking "sprite" that appeared over the most shining/bright element of the car.
I hope it is not too detailed wish,
best wishes (and please move this post eventually to the new topic)