I had an Audi A4 for a couple years, I upgraded from a VW lol. Pop the hood and you will see parts are interchangeable between the two for some of the models. Porsche and Audi parts are not uncommonly used by the factory in VW's. HOWEVER, they still use the same electronics company to do all of their wiring. That company is EDO. All, and I mean all, the problems I had with my VW's and Audi were all electronics related. Granted they have a good warranty on them, but who the hell wants to drop their car off at the shop all the time? More importantly, they don't always have a loaner and your bill has to be big enough to pay for the loaner from the warranty company. So you will more often than not get stuck without a car to drive if you have some electronic issues that need dealer attention.
Several friends and one of my brothers have BMWs of different models all no older than 3 years. They love them and they love their service and warranty. They come to you to pick up their cars if need be. Their seats are more comfortable, their layout inside the car is more user friendly (to me anyway) and I think they handle a lot better especially in the crappy weather.
The electronics issue is keeping me away from Porsche, Audi, and VW for good. It's only a matter of time before the electronics start to go, especially with the headlights. You gotta put it up on a rack to get the shroud off just to change the bulb. I could go on, but that's the gist.