You can call a dealer to get the actual part number, and decide how you want to go from there. But you are correct in thinking about changing them all. Once you spend the time to get access to the back of the instrument cluster you may as well replace them all. When one goes out the others can't be too far behind. I've thought about LED's when the time comes, too. But I also wonder how they will look. The OEM bulbs provided a nice background, and I don't know if that will be the same for the LED's, in part because of the dual brightness settings when the headlights are either on or off.