I really have enjoyed following this thread! I have been searching for the K-Line Sounder Bombardier commuter rail cars and recently found a set (at Western Depot). These are the cars on the Sounder Train line which travels between Tacoma and Seattle and Everett and Seattle several times a day during the work week. The line has recently been extended further south to Lakewood, and new includes a new station at 56th and South Tacoma Way, which is a short drive from my house. In Seattle, the train stops at King Street Station, which always has some interesting cars parked on a siding. The line uses the BNSF tracks, which has lots of freight train action, so it makes the hour long commute go quickly.
The K-Line cars are really detailed, and really capture the look and feel of the real cars.