I'd say buy an inexpensive 120volt inverter (wouldn't take much) and there is a multitude of options available in custom interior lighting.. 

I just spotterd at the local walmart a 18" stip w/6 down light LEDs for cabinetry and curios. it was formable and uses a power brick to 120v. 

you could likely do the electrical math and get a proper connection to 12vt.   they were $24 +/- 

Subject: light emitting diodes

What does the list think of light emitting diodes (LEDs)? I want to replace some of
the interior incandescent bulbs with LED bulbs but have been having trouble finding a
source. I am fascinated with the idea of 100,000 hours of light from one bulb. I would
also like to replace exterior incandescents with LEDs, but again can find nothing but
a flashing break light (I would like something more subtle). Any sources? Thanks.

Barbara
89 Syncro