OP, I'm in the auto sales industry locally for a Honda/Acura dealer. I've got a friend and 2 former coworkers at BMW Northwest in Fife. I've found their sales department to be the easiest to work with thus far. Seattle is my destination for service.
If you're not already in contact with a dealer, PM me and I'll give you my friend's contact info at Northwest.
2013 M5 : Silverstone / Black : DCT / Executive / Driver / B&O : ESS Tuning Stage 1+ / Armytrix Full Valvetronic Exhaust / Rotiform BLQ-T Forged / H&R Sport Springs / IND Cosmetic Package
2016 Mustang GT w/ Performance Package : 6MT : Vorsteiner V-FF 103