I personally go for function over looks especially when it come to some stupid fuck being behind me and Im braking and turning.
I love my evotech plate holder and then I have some Rizoma signals. It looks way better than stock and still plenty legal, but that is just me, and I am unlike 99% of the people on here that customize their shit more than they ride the damn thing.
Basically no matter where that shit is mounted people are still going to think your bike is sexy, and the only time you see the shit is when you are walking around it, which I rarely do, I check my chain tires and call it good.
That is just me though man, if a taillight is that important I am sure someone can answer the question for you will probably just be a few till people start getting up and on the site.