I just had a 4-way suspension alignment done on my 550 yesterday by Bryon Tate at Tru-Line Frame & Wheel in Bellevue. What a -HUGE- difference it made in the handling!!!! If you don't know when your car last had an alignment, I would highly recommend getting it done. Tru-Line (Seattle & Bellevue), Group2 (Ballard) and Speedware Motorsports (Redmond) are all great shops that do computerized laser alignments.
I have been using Byron again recently (tire install on my BMW), his work is carefully and exceptionally done. I don't know why I even started going elsewhere... My 355 got an alignment after the major service...I believe FoS farms that out to Byron's son at Tru-Line in Seattle.
They are fantastic!! They have done my '80 Maserati 4Porte and Alfa 164's in the past. They handle like new when they work their magic! Mike