I've been fascinated by this case for a long time. When I look at their images I think it is possible that they are French Canadian. I believe they are either Canadian or even Iranian. Back in the 70's Iran was very cosmopolitan with everyone adopting western dress and cultures and many young people went to Europe or the US to go to school. My first instinct, though is that they are from Quebec.
Back in the 70's it was a rite of passage for kids from eastern Canada to make a trek to the west coast, buy a used van then travel down to California, making their way across the country through Arizona etc and then back up home before school started in September. I wonder if that was the route this couple made. I remember reading somewhere on these threads that a mechanic in Nebraska recognized the couple saying he'd worked on their vehicle and that they had traveled from Washington or British Columbia.
In 1973 a young woman called Lucie Gelinas went missing in Trois-Riviere Quebec. She was supposed to travel to Vancouver with a friend and hasn't been seen since. I don't know if the friend was male or female and whether they also are missing. There is a picture of her on the missing website for Canada. She is the same height, 5'5" weighed around 115, had blue-green eyes and shoulder length dark hair. Her chin is very similar to Jane's and she appears to have slightly protruding teeth. The only thing that isn't in keeping with the autopsy results is that Lucie had a scar on her abdomen from surgery. Since there has been so many problems with this case I'm not letting that be a issue.
I can't figure out why they have never been identified. Even a father who was displeased by his son's choices would worry if he just disappeared off the face of the earth. I would love to know what their genetic ethnicity is. Hopefully there is still DNA to be tested.