This event was called into the Air Force at 7:00 AM 01/01/1979 and all 4 witnesses gave personal detailed information.

Traveling by car and while returning to Sacramento,CA from Reno, NV, in the early hours of New Years day, the 4 of us all witnessed a craft over a period exceeding 30 minutes.
Craft was first spotted as a white light high in the mountain (approximately 40 miles away) and above the National Forest witnessed by the driver while observing the light through drivers rear view mirror for about 20-30 minutes.
As the light became brighter, and closer, driver could clearly see the outline of the craft and further that what had appeared to be one single light was actually 3 lights located on the underside of the craft.
Craft then hovered next to driver's passenger side of the vehicle (about 1/4 mile to 1/2 mile distance) next to Highway 80 for about 15 minutes, approximately 100 foot above the ground and in clear view of driver and all three passengers, as passengers discussed the features of this observance among each other.  All 4 of us were frightened.  Craft proceeded to travel at the same speed as our car (95-105 miles per hour) as driver's response was a futile attempt to "outrun" the craft (this lasted about 5-10 minutes).  It should be noted that other witnesses were present as another automobile actually passed our automobile at approximately 110 or more, miles per hour.
Driver became exhausted and recognizing that he could not outrun the craft, and fearing an accident at this speed, driver decided to slow down and finally stopped the automobile on the side of Highway 80, hoping that the craft would continue in it's trajectory, and simply pass.  Driver got out of the car and watched as the craft continued and finally passed.  
Note: The craft traveled approximately 100 feet off the ground over the terrain which increased and decreased in height according to the height of the terrain as if perfectly measuring a gravitational effect of the earths pull on the craft.  There was no sound effect from the craft, and in fact, from any other source. It was totally quiet.
Upon arrival at our destination, this matter was called into the USAF dispatch and a complete report was made by all 4 witnesses.  There was never any followup by the USAF.  I still remember this event as if it was just yesterday.  The only detail that still troubles me is the fact that it took us 6 hours to make the trip that even at 65 miles per hour should not have exceeded 4 1/2 hours.  This means that driver estimates that we were missing about 1 1/2 hours of time as measured from Reno to Pleasanton, CA., as the trip took us over 6 hours total.  Saucer was approximately 130 feet wide by 35 feet high.