Radiator Fan running
 

Is it normal for the radiator fan (I assume it is the radiator fan) to run after turning off your car? I have a 2015 A8L 4.0T. Now if I restart the car and turn it back off the fan stops.

Yes it's normal
has been for most modern high performance German engines as far back as 1999

Yes, my S8 after runs the fans commonly, even on a moderate day. D3 W12 only did when it got quite hot. Glad it does given the amount of heat under hood at shutdown. Those of us with D3 W12's saw a number of parts get pretty heat soaked over the years underhood, especially toward the back.

Happens on my S8+ pretty much every time I turn the car off, unless I have barely driven the car. It was also a surprise for me initially, coming from a V8 M3 which pretty much never did it.

Hmm I guess my other German cars must have been broken as they never did it. Now I know.

Yes same here. Didn't have the issue with my Q7, X3, 540, X5, or 911.

Same here. I'm forever having people ask me if my car is still running! This motor really puts off some heat.

It has a lot to do with the fact the turbos are under a plastic cover on top of the engine. There is a temp sensor under there and if it thinks it might get hot enough to melt the plastic cover it runs the fans.