Finally got around to installing the interior LED's I purchased from eBay. Nice set, NOT from China, with each little bag clearly marked. Good communication from the seller, who included a couple of spares too:
18X BMW X5 E53 White LED Interior Lighting KIT | eBay
Installing the overhead console/map lights was a bit of a head f*#k but referring to my trusty Bentley manual I finally managed okay. Makes a huge difference to the interior illumination and I wonder now, why I didn't do this earlier.