Some time ago I upgrade all of my interior lights with LEDs. With the exception of the trunk, I simply replaced the existing bulbs with 5050 SMD 9-LED bulbs. From the puddle lights, red door lights, dome lights and map lights, everthing has been replaced. The lighting is far brighter than the original halogen bulbs and the light is crisp and white. The lighting is so bright that I can clearly see inside the vehicle from the outside even on a dark rainy night. The trunk lights were replaced by 20cm tube LEDs that have a total of 20LEDs per tube. The overall cost was less than $100 and I purchased everything off eBay from China/Taiwan/Hong Kong. Some pictures didn't turn out so well because my camera does not take dark pictures very well.

Pic 1 - driver-side 20cm LED in trunk.
Pic 2 - passenger-side 20cm LED in trunk.
Pic 3 - brightness in trunk.
Pic 4 - rear driver-side footwell.
Pic 5 - rear driver-side puddle light.
Pic 6 - front driver-side footwell.
Pic 7 - rear dome and map lights. (Dome is LED, map is halogen)
Pic 8 - front dome and map lights.