A nice supply of tiny wire is a great place to start for parts:



A toggle switch is nice to have so you can activate the light and leave it on rather than a button that needs to be held:




Finger lights can be found at almost any dollar store and comes with four different colors and all the batteries you could hope for. These are a great source of parts:




LEDs can only be powered one way. Only having the positive on positive and negative on negative will complete the circuit:




The first step is to see how many batteries are requires to activate your light. In this instance, no less than three (3) will bring the sunshine but it will also light multiple lights:




Seen here is the layout for the complete wiring:




Here we begin installing our lights. This model came with headlight pockets, so I drilled them out and fit the LEDs in place:




The switch will be installed in the center console:




The taillights will be a single bulb which lights up all four pockets. A mounting shield will be put in place to both hold the LED and keep light from illuminating the trunk:




Now, you need to begin soldering your wires to your LEDs. From here, you need to route the wires throughout the figure. Remember to leave slack in the wires for joints or areas that compress/extend:




The wires all run up to a central point and connect to the switch:



A battery box is a must have but salvaging one from something else doesn't always work due to space. Here we scratchbuild a custom box out of styrene using several components from the finger light:




Begin by cutting out a slot for the metal band to fit through. Glue up your first wall:



Line up you batteries to determine how long the box needs to be. I've added an extra battery to this setup for good measure:




Set the other steel band in place:




Cut another slot into the other wall panel forcing a small amount of pressure on the batteries:




Now, glue the end caps on and apply pressure to the walls until dry:




Test to make sure you have proper contact:



Install battery box and fire up the lights. If everything works, it's time to begin soldering everything into place: