I just hit 40K miles on mine and haven't had any significant issues other than electrical (window switch, door memory, swiveling headlights). I used to have an A6 and had all kinds of suspension problems. None so far on the S4 but then I have aftermarket COs.

You will spend a ton on gas - no exaggerations on that. I commute about 60 miles a day and spend $500+ per month (granted, CA has the highest prices in the country).

 

I have the complete opposite experience living only two miles from work. Unless I make other trips during the week, I only fill up every-other week. I love driving the car so much I wouldn't mind living further away.

Side note: Yess4 - Couple of questions. Where did you get the V8 badge; what year is yours?

 

They started putting the badge on the 2005.5 model (B7), which is what I have.

 

I bought my car with 42K miles on it and have driven it about 8K. At 43K I had an issue with an engine coil going. It was covered under the CPO warranty - a must as said above. 2 had already been replaced, so I replaced the others for a cost of $400 at the dealer. Nothing else is wrong. The car is a blast to drive.