Good thread idea.
There is one that has puzzled me…
I think it was a late 60s/early 70s American counter-culture/hippy(possibly?) desert road movie, of the Easy Rider variety. I saw it when I was probably too young to understand what it was all about but found it weird and interesting and for some reason it stuck with me like a dream half-remembered. I think I recall a scene with characters blowing smoke rings outside a diner/bar/ranch-porch or something.