I got my '06 612 in late June, and have put ~2500 miles on it. I love the car for the most part, but have the following issues: 1) Buttons on the back of the steering wheel should have a real function (controlling radio, for example); 2) I wish the windows would go all the way down; 3) A lot of information on the digital screen is redundant. Speed, many warnings etc also appear inches away. Why present the same info twice? As I said, I love the car, but the above 3 are my issues.
On an '08 or later, the buttons on the wheel do work. You can change volume/track etc on the radio, the buttons change depending on the mode the Bose system is in - so they fixed that one. on 2) I have the seat all the way down low so it takes away the desire to rest your arm on the window opening. Plus my mirrors whistle and you don't hear it with the windows up, so I tend to not drive with the windows down at all. On 3) you're right, I wish it would stay on a particular page rather than defaulting back to its standard page.