So I recently purchased a set of LED interior lights for my MY03 A6. I have purchased a few different sets/loose lamps in the past from different companies, but this set from TunerDomes (contact: David Delaney) so far is the only vendor that has been able to get me LED lamps for my dome lights that actually work correctly.
All sets I have purchased previously never worked correctly, especially when it came to the map lights in the dome light assembly (not the constant-on red LEDs, but the ones that switch on/off separately from the dome lights that turn on with the doors). The map lights would either always glow slightly, or only glow slightly if I tried to use them alone (without all of the dome lights). They would only work properly if I turned on all the lights (which defeats the purpose of having a separately-controlled map light).
Now, though, they are all working properly, thanks to the assistance of the above named salesman. They did not work right from the get-go, but after some emailing back and forth, they sent me another set, specifically for my map lights, free of charge, that light up perfectly (they actually sent two different types of lamps for me to try). Shipping was insanely quick for these as well, especially considering the season.
I just figured I would post this here, to give them some credit for being more than helpful my issues, actually correcting them, and because I did find them on here (as a "New Sponsor" of AudiForums.com).

 

Good looking out! I'm actually experiencing the SAME problem you had - in regards to using the map light, etc. I'll have to give them a lookie-loo!

 

I will add now, after a few weeks of trial, that it is kind of finicky. Sometimes they work, sometimes not. I cannot for the life of me figure out what the difference is though. I'd say it works about 70-80% of the time, which is 70-80% better than my previous LEDs. I do have another set from TunerDomes that I have yet to try (they sent me a few sets to try, and I stopped when this one worked), but I will be trying those soon and report back again.