Single craft

This happened over 30 years ago, so some of the details are not clear.  We had stopped at a lake and camped then my ex husband, and son (he was about 2 years old), did some fishing.  We left around 10 am heading towards San Louis Obispo.  We both saw the craft; it was the typical "saucer" shape, aluminum color.  I had always thought for about 2 hours.  Recently I underwent hypnosis, and it seems the time frame was probably around 4-5 hours.  Our final destination was Salinas to visit relatives.  We had planned on taking an inland scenic route on the way up (from the Los Angeles area), then come home the coastal route.  Shortly after leaving the campsite we started seeing the craft, it was like it was magnetized to the car.  No matter how fast or slow we went, or what direction we went, or how fast or slow we changed directions.  It stayed exactly the same place in my field of vision.  At one point he stopped the car and cleaned off the windshield, thinking, “maybe it’s just a reflection.”  Needless to say it made no difference.  My son, who is now 35, has no recollection of the incident.  My ex husband would not discuss it with me at all, other than to say we both did see the same thing.  I was 3-4 months pregnant with my daughter.  When we were about 10-15 minutes out of San Louis Obispo, it was gone.  In the blink of an eye, one second it was there the next it was gone.  It has haunted me ever since.
Date is approximate.  PD