My 04 A8L with 06 S6 LED DRL's. No codes, no issues. LED's and all maintenance by Danny at Elite Motors (773) 588 9622 (yes, he's an AWESOME indy mechanic). The only thing I recall being troublesome is that Audi placed the air suspension compressor or level sensor or something to do w/ the car's levelling system right there and we had to cut the LED's plastic and reseal with the sealant used on windshield installations. Again there are more knowledgable tech oriented folks in this forum that can explain better.

See attachment below for a pic from moments ago (sorry, snowed this morning, car is very salty at the moment).

Regarding your final comment, I *think* (could be very wrong) but I read somewhere Audi dealers were not selling Q7 LEDs w/out a VIN. Other members more knowledgable than yours truly may be able to elaborate.

One of my best friends is a Mercedes service advisor. Until the recent addition of LED's on the S-class in 2010, Mercs didn't have LED's at all so the dealership's employees used to complement me on my car regularly. In fact, many inquired as to whether my car was an '09 or '10...that was amusing

Regards,
Hasan