2004-05-20 - Fairfield, CA - Rectangle

My family was driving west on HI 80 from Fairfield, CA (heading for Vallejo, CA) when I looked up towards the sun which was partially covered by a long, narrow cloud (sited by Highway 29 Napa Junction). In this cloud, I saw a rectangular object, white in color, which looked as though it had three windows. Its form was very pronounced. I told the rest of the family to look towards the sun, at the cloud and asked what they saw. They said it looked like a building with three or possibly four windows. We took the Redtop exit to purchase gas and upon entering HI 80 again,did not see the object in the sky. The object did not move for a 3 to 4 minute period, possibly longer since the object was most likely in place before I spotted it and may have been stationery during our gas-up at the station.