 I've owned my fairly low mile 2012 a6 for about a year now and I could not be happier. I've added a little zip to the car with an EPL tune + pulley that gives it another 80-100 hp from stock. I'd advise anyone that likes an extra sporty ride with no downside to get this tune....Amazing!!  Back to the car. Love the drive. The quattro has an incredible feel of safety. Rides on rails for a luxury sports sedan. I don't have the air suspension so highway driving is a breeze but chippy roads can get a little rough, especially with 20 inch wheels. A6's have a touch more body roll than I thought they would have but it's not an S so it makes perfect sense. Interior is excellent. Seats are very comfortable. Heated seats work great but no cooled vented seats in my ride, which I really miss. Air con. is great though. Once you get used to MMI it's so easy to navigate. Speaking of navigate, the live google navigation is very nice to have at your fingertips. GAS Mileage you ask?...even with tune,  30mpg on highway at 65-70mph (26mpg on highway @ 85mph). City is around 20. Steering is a touch vague but extremely confidence inspiring. All in all the car is fantastic. I've owned an e39 M5, S55 AMG with tune (rocket), CTS-V, G35 and way way back an Integra GS-R (totally stock). I think for all around sporty driving and comfort for a family of 5, this one is my favorite of all. It obviously has more tech but the feel of safety and road holding is just amazing. It's just so easy to drive!    For pure driving fun the e39 was probably the cream of the crop. Although the A6 w tune is a good bit fast than the M.