2010-05-30 - Seattle, WA - Rectangle

I was driving North on I-5 about to take the 405 exit, and over the hills/treetops I saw a dark gray object that was the shape of a large fat rectangle, it must of been flying toward me because it kept getting bigger and bigger- it was HUGE in comparison to a commercial plane, at first I thought maybe it was the dreamlifter or a plane simular in size, but then it got much bigger and the color was a dark gray and the shape was rectagular/square, definitly not a plane. Then I thought maybe it was an advertising sign of some sort that was flying behind a plane, but there were no planes around and the way this thing moved was WIERD. Then it just lowered itself down behind the trees. I couldn't see it after that and unfortunately I had to take my exit. I don't know what the thing was or if anyone else saw it, I hope someone did and will also report it so that I know I am not crazy.