I have a 2009 Q7 and a 2000 A8. I've replaced all bulbs in the A8 with LED and while I do get some dashboard warnings... they all work!!

The Q7 on the other hand; I can only get the daytime running lights, and the license plate lights to work... none of the others will work.
They will come on for a brief second and wink out almost immediately. So I had to put all the incandescent bulbs back in, and they work fine.
Needless to say, I have $150 of LED bulbs sitting in a bag that I'd prefer to put in the vehicle.

Any recommendations are greatly appreciated.