Not sure if any one else has had their widow switch light/bulb go out, if so here is a part number for that bulb/light to be replaced. I found the DIY at the following link:
http://www.bmwe36blog.com/2008/10/31...tch-light-diy/
The bulb replacement is from Radio Shack, catalog # 272-1092, they come in a set of 2. (Micro Lamp).
This bulb is a bit smaller than then OEM type, but works just as well. I also painted it with red nail polish & it realy turned out good. Can't even notice any light differnce. Hope this info helps.