The biggest issue you will run into, is the space to hold everything.
Ive played around w/ lighting models in the past, and the actual lighting & wiring isnt that difficult. Its routing everything, and finding the space for it, that is the biggest issue.
Im currently working on a 1/24 Italeri Western Star Constellation tractor w/ a 48' reefer trailer, that Im thinking about lighting up.
Ive always really liked the look of the 18 wheeler's you see on the road that are all lit up w/ lights all over the tractor & the trailer. So Im currently trying to decide if I want to do it. Im looking at using what are called Surface Mount LED's. The biggest problem w/ these, is their size. They are roughly 2.5mm long, 1.5mm long, and about .75mm thick, so they are extremely small, and tough to work w/. But I can get a roll of 100 of 'em on ebay for about 7 dollars, so thankfully they arent very expensive. Im considering spacing them about every 2-3 scale feet on the trailer, so that could be as many as 48 of these things on each side of hte trailer, plus the lights on the cab.
As far as fiber optics, I dont think you'd want to glue them directly to the LED, otherwise they are going to be extremely bright, since the fibers will transmit all of the light from the LED. Your best bet would be to find a way of putting something between the LED & the FO, to help difuse the amount of light "visible" to the FO strands. As for routing the strands, I'd suggest making them look like they are part of the wiring in the car. That way you wouldnt have to hide them, or hide them in plain sight as it were.