Quick question on LED/lighting...

I'm finnishing up an JDM IRT, and plan on running a blue for both headlights, and a Yellow LED for the "fog" lights, as well as a christmass light(purple) for the interior.

do I need to connect a 100ohm resistor to each Positive pose on each LED (I'm using either a 2 or 3 pack of AAA's), or can I just put the resistor in line with the positive lead from the battery pack?

I'd hook up one for each LED and I think you have to run three batterys to have enough voltage for the Blue LED's.
I'd also consider using a white LED for the purple, simply to simplify the setup.
:p

I was thinking of something like this...but I was afraid of the bulb heating up and melting the plasic. DO LED light bulbs heat up?

If you use a proper series resistor the LED's won't be more than very slightly warm. Most regular light bulbs get too warm to be run continously.

well, I've found that I have enough room to fit a 2 or maybe 3 AAA battery pack in the engine bay.

The car it a JDM ITR, so it has the 3 headlights, so I'll have 2 of the outside headlights blue, and the middle fog lights yellow (couldn't find a 5mm or 3mm orange..... much less purple for the interior).

I'm thinking or running quick-disconnects to an external switch-box where I can power the headlights&fog lights with the AAA battery-pack an a 9V for the Purple interior light.

[the car is "Copper/Orange" (like the Signal Auto drift cars) copper base and 3-4 coats of Tamiya clear orange. Interior is Tamiya light blue base with clear blue mixxed with a 1 coat of clear purple.)