I will try to make a lighted cupholder mod for my soon to be prius. The led's will be able to change to many colors like green, white, blue red, etc. BTW, does anyone know where I can find a small multiple multicolor led kit to start the research?
The Scion light kit for the cups uses the bulb type you are refering to. The company, Luxaura, makes the under dash kits so I would assume that they also might have made the lighted cup kit as well.
How about some of the computer case modding lights? Some come in flexible strips or ropes, while others are stiff (like cold cathode or neon). One place to find those: www.thinkgeek.com Otherwise, try an electronics store and see what they have in the range of small LEDs? Hope that helps! I love your idea.
I also should comment that while flexible neon wire has a very cool effect it is not a permanent thing. By this I mean that after about a year, it is obvious that the wire does not glow as brightly as it once did. If that doesn't bother you or you are willing to spend the time and money to change it out each year...then go for it. As for small leds, while you could go that route and set up a circuit so you can have running lights it would involve more drilling into the cup holder. This is possible for the upright one, however would be unadvised for the flip one as the mounting would be rather difficult unless you run them up the length of the holder along the back edge. My recommendation is to use a multicolor bulb such as that found in the Scion cup kit. As the lens on that allows the blub to display multiple colors but you'd only have to make one drill hole per a cup holder. As for cold cathode, they are excellent for the application of under dash and under seat lighting. They are very bright and well priced. The only problem with going that route is that you'd have to mess with the wiring quite alot to mod it for automotive use...unless you find kits out there. I've heard good things about the kits at www.randode.com When I get a chance I will take pics of my underdash and cup lights.
Oh I should also mention that depending on how you want your lights to work meaning how they are controlled. You might want to consider if you are only do cups vs both dash and cups as it's ideally better to have them controlled via the same switch.