I have converted the Map Lights to LED using an item I found while browsing at an Auto Lighting shop.
I got two packs, used the 31mm festoon connector (of the seven different connectors supplied) and then did this:
Removed the incandescent bulbs (8 watts) and inserted the 31mm festoon connectors.
Fastened the 4x3 LED Array in the Map Light cover using the double sided foam provided in the kit. Tucked the excess wires up behind the festoon connector into the roof lining.
The light level is improved and certainly works well with my light coloured alacantra leather interior.