Ebay offers Type S Plug Glow Multi-Color LED Light Kit Trim-to-Fit 12V Power for $12.99 (reg.  $34.49) with free shipping.

Product Description:
If you're looking for a way to add a little bit of extra visibility to the interior of your car, you may want to consider interior lighting. LED lights are a great way to improve your car's cabin. Overall, the best light kits with custom multi-colors will let you personalize your car. The TYPE S Plug & Glow 24"" Multi-Color LED Kit has durable lights with a plug-in power option, is water-resistant, and has an adaptable fit that will let you tailor the lights to any area of your car without taking up too much space.