I used to make trips very similar to these - everything I owned fit in an old Porsche 914, although my waterski (I worked as an instructor during the summers) and guitar got strapped to the top of the rear trunk lid.
I loved the rhythms of those trips, along with the sense of adventure in those pre-internet/cell phone days. Stopping for 5 hours just to wait for the light to get perfect for a photo of some sand dunes along the coast. The freedom of not knowing where I would spend the night. The forced solitude.
My mom has been gone 6 years now, and I can only hope to find some last message from her floating around in the universe somewhere.
I hope you find hers one day in the far-off future.