Btw,
I borrowed my father in-law's Infiniti M35x to drive my wife to NYC for her back appointment (we needed the comfy seats) - she really liked it!!!
So a sedan or wagon, such as the 528ix isn't out of the question.
The M35's a nice drive, but its suspension on NYC roads isn't as well sorted as you'd expect and it has an annoyingly numb on-center feel, I had to constantly correct at the wheel (could be it needs an alignment).
But by far and away, it's the gas mileage that really stinks with this car - we averaged 16
The seats are awesome and it's an easy car to get in and out of.
Ed