One thing to be aware of with most of these LED replacements- LEDs have a pretty narrow beam, so the percieved brightness falls off pretty quickly if you move off from viewing them straight on. They also don't cast any light 'backwards' to be bounced off the reflector and make the whole lens 'glow,' so with many of the simple screw-in LED replacements for incandescent bulbs you can actually end up with overall decreased tail-light (or whatever-light) visibility. In most cases it's probably not all that big of a deal, but on a motorcycle for example, that extra visibility (or lack-of) could be a life or death difference. Old BMW bikes are my other money-sucking 'hobby' and they have pretty anemic charging systems so in an effort to save a watt or two (and be more visible) I tried the simple LED replacements in my tail-light. From directly behind the bike the center of the tail-light appeared brighter, but overall visibility was decreased (instead of a big square of glowing red, the light was concentrated in the middle, almost no light at all to the sides, etc.). Ultimately I ended up with an aftermarket LED array that replaces the entire reflector assembly in the tail-light with about 40 LEDs- now THAT was brighter/more visible (and more $$)! I don't think it saved me much in the way of wattage though. The tail-lights on our Amazons are pretty puny by modern standards, so personally I want them as bright and omni-directional as possible and believe it's better to get your charging system in top order than to lose some light/visibility to save a couple watts. LED technology is changing, so maybe my concern is now outdated, but I don't think it is yet. Anyway, just $.02
Tom
NYC