Oh man. Not what I wanted to read when I searched for this
Maybe things have changed in the couple of years since this thread was made?
I just replaced the 3rd brake light bulbs with LEDs and they looks fantastic (I have the aero kit 1 spoiler which uses the 996 3rd brake light). If there's a diffuser issue I can't see it, but then again I don't know what I'm looking for. I'd like to do the brake bulbs at the tail lights too. Would bulb or resistor heat still be an issue with the brake lights since they obviously won't be continuously switched on?