Just curious if anyone makes better headlight guards than the ones I've seen with large vertical gaps?

Is there any reason that there may not be any that protect like the "square" auxillary light guards you see on lets say KC lights?

Is there a law that specifies the amount of "obstruction" that a headlight can have?

 

I haven't seen any different but I also haven't been looking. As for the obstruction question, it will be state specific. In most states, the laws are written with solid coverings, like tints, in mind. They typically don't cover things like guards.