I'm in the middle of comparing a A4 to the 328ix and if I wanted just base models with only 4WD and xenons, I can probably get them for:
A4 Quattro: $35K
BMW 328ix: $40K
In my opinion, an A4 is 95% the car of a BMW at 87% of the price. So it's hard not to look at Audi. Sure, a true enthusiast might detect slight differences but most people are not enthusiasts and likely would not. So BMW is essentially charging an extra $5K simply for its name. That irks me. In a a way, I wish Audi does steal sales from BMW, so then maybe BMW will lower its prices.
BTW I've owned both Audi's and VW and an Audi is not a VW in my opinion. You feel the difference in everything from the door slam to the bell tones. The VW screams utlity and the Audi screams class. So yea, I am a fan of Audi's but I'm also a fan of BMW's and can see +/- of both brands.