Just IMHO, I had one of those with a McLaren, and it was A) unattractive, B) prob added tiny bit drag, c) collected grime and made battery fractionally harder to get on and off for charging.
Big points though are this: It added more than 60 grams. Word to the wise, take whatever money you want to spend on it, and invest it on one of those cheap internal batteries off ebay... You lose that 60 grams, prob 20 or 30 from the battery mount, a few more by going to smaller battery with no cover. And sell the old battery. Pretty soon you are into less drag, less dirt, better aesthetics and damn near a quarter pound of weight out of the bike for about the same money or a tad more than cover. If you can find one.
I found nothing useful about it, nothing, other than it was standard factory part for the McLaren and you kind of have to keep those things together. I use the internal battery I just described on my S-Works and its an elegant solution.