I forgot to add this part to the story.
After all that driving of over an hour and a half of them having sex in the back seat; when we got to our home - I realize I forgot to move the passenger front seat all the way forward! He's 6'-1" and her small size made it work and all, but by having that seat forward by 12 inches or so would have given them more room for different positions and myself a lot more room to watch and take a few photos.
Actually take better photos. I think I could have gotten video with light and stills with that extra room to brace my arm against the seat, rather than trying to aim backwards behind me.
I include two. First is when she took a photo since she was sitting behind me while at an intersection before she woke up the "other guy". Next one is the only decent shot I got while driving 65MPH. His knees areup against the front seats. Her butt looks red for the reasons I stated above
I've consider posting her in the "school girl" outfit from that night, but she's using it on her profile on another site for kinksters.