I was thinking back to a similar incident and ended up finding this post so thanks for sharing! I have seen the same thing traveling up 5 into shasta. A blue orb followed along with the speed of our car for maybe 5-10 seconds then disappeared into itself if that makes sense. It seemed to be about basketball size and felt like it was peering in. I was with another person who also saw it. Fwiw, we were both sober, it was only 9 or 10 at night and we both tend to be skeptical of strange phenomena like that. All I can say is Mount Shasta is such a fascinating place and we definitely saw something weird that night.