(EDIT, saw you specified ARC, I've updated my post to reflect the ARC model not being able to fit 15s like the Aero)
Fits fine. No clearance issues at all.
Like a previous poster said
99-05 9-5 Linear models are good to go
99-05 9-5 ARC and Aero has bigger brakes and they won't fit.
06+ 9-5 models have bigger brakes and also won't fit.
No real stability issues. Traction control and ABS seem unfazed by them. Did some snowy driving tonight and intentionally let the car get frisky to test it all out and everything worked well.
If you're driving your car normally there aren't really any issues other than the speedo thinking your going faster than you are (and racking up more miles than you are). Of course, it don't really think it's a problem "misrepresenting" your mileage if you're odo says the car is HIGHER mileage.
Pictures in a day or two. I thought they were going to look way more silly than they do, to be honest they just simply aren't all that attractive is all. Doesn't really look silly. Was kinda bummed about that. lol.
15 inch deltas on a 9-5 confirmed working!