what do the headlight louvers do on the z31?

 

look cool, nothing else

 

Agree, they look cool. They also will redirect your headlights in a way you may not want, depending on your driving locale. Z31s use a double-filament headlamp where the high beam is actually another filament inside the lamp. The clear glass lamp face is patterned on the inner face to direct light from that filament up higher and wider than the low-beam filament does. So I noticed that on dark roads (like through the forest at midnight - on the way to Grandma's house) I could not see as well with my high beams as without the louvers - and the occasional 'thud' under the bumper - a smallish, dark-furred animal, no doubt - surprised me because I did not see it out there. Thud, rumble as I rolled over it. I hate to kill creatures who have more rights in the forest than I do. With my cool headlight louvers I have less chance of seeing them out there - so I hit more of them, on average, than I ever did with standard hi-beam lights, no louvers. So it's your call whether to use the louvers and think of the furry little kids back in the nest wondering why Mom or Dad didn't come back yet. It is getting late and they are usually back by now...