RWD's list pretty much matches my own. Gotta love Mustachians!
If you have an independent shop that services Saabs, it is a decent option. Repairs will be in line with Audi costs, but probably slightly less frequent. They are definitely very inexpensive these days and parts availability should be very good for at least the next 5-10 years.
The other benefit is that while they are a "nice" European car by any measure, they tend to fly under the radar. In my experience, wealthier people tend to think of it as a solid, if quirky choice. At the same time it doesn't have the same snob factor that may people associate with Audi/BMW/Mercedes. My wife has a 2002 with over 280,000 mi. And it still has the original engine, transmission, turbo, clutch, etc. very well built if maintained properly. If you get a 2.0 or 2.3l model, the mpg should be slightly better than the other cars on the list- the V6 is thirstier.
The 9.2x, aka Saaburu is 80% Subaru WRX, so it has awd and can be serviced by a wider range of garages, and cheaper. Honestly the refinement is not as good as other Saabs, or up to the standard of other European cars, so it depends on how picky you or your clients are.
V-series Volvos are also good, but the awd systems are weak, and the newer models are nowhere near the reliability of older models. Then again, almost nothing ever made was, so there you go.
I would be tempted by a Mercedes E-series awd. Very well engineered, and a good awd system. They also are very reasonable used because people assume they are really expensive to repair.
As always, any of the list above can be great cars, it's more about their prior maintenance.