I am still trying to mount my 4" 54 LED truck brake/turn/tail light. I think I have it figured out, just need a couple of washers. You do NOT want to be looking at this thing from close range at the high brightness! I've got a couple of the amber beehives that I am messing around with, also.

You know, one thing I would like to try, except that it costs 60 bucks, is a white 54 LED truck light. These are intended for overhead lighting in trailers. If I was sure how bright it was I wouldn't mindspending the bucks. The attraction is that it only draws just over .6 amps, which would either provide super long battery live or allow the use of a small 2 or 3 amp hour battery, even with tail lights.