Hi all, I just wanted to confirm that the correct bulb for the tail lights is indeed the (smaller) 5W bulb (with a BA15S connector) and NOT the larger 21W bulb (used for the brake lights)? See below (5W bulb on the left). I'd never noticed, and just recently realised that I have the same bulbs installed for both the tail lights and brake lights. I can't be the only one, however, as after disassembling some of my spare tail light assemblies (of which I have many ), they also configured in the same way. The tail light itself does stipulate 5W: The reason I ask (other than curiosity) is that I'm attempting to make some LED tail lights (using COB panels rather than replacement bulbs, as I'm not impressed how these work). It is important that, on one hand, the tail lights are bright enough but, on the other, not so bright that the difference between the overall brightness of the tail lights and the brake lights is too small (i.e. so people didn't notice the brake lights). I'm currently experimenting with a configuration that uses 3 COB panels: two are used at reduced brightness for the tail lights: ... and all three are used at full brightness for the brake lights: I also took the opportunity to swap the orientation so that the brake light is the uppermost light (not the lower light as per the standard configuration). I think this is safer these days as modern are so high. The reason for the brightness question is that I'm empirically setting the tail light brightness by comparing to a tail light with a normal (incandescent) bulb. During the testing, I realised that the housing I was using had a 21W bulb installed for the tail light. I wonder how many other people are doing the same? That said, even when running 21W bulbs for both tail lights and brake lights, there is still a noticeable difference when the brake light is illuminated thanks to the way the reflectors are set up. Also, a 5W bulb does seem a bit weak these days, where most modern cars use LED tail lights which do seem to be much brighter overall. Thanks for any input! Cheers, Dom.