#853 Percé Rock, Quebec, Canada.
The landmark in the upper left background is Percé Rock, Quebec, Canada. The body of water is the Gulf of St. Lawrence, and a bit further east would be the Atlantic Ocean.
The exact location of the car, I estimate, would be a bit further to the southwest down the coast in Quebec.
Now here's where a "debate" could be had. I offer the following solution for discussion.
Percé Rock Island
The rock is in the red square. I selected the screen shots below from Rte 132 inside the green circle.
It could easily be a bit further NORTH on Rte 132, and/or WEST into Quebec, but I didn't spend a lotta time looking in those areas .. the sight lines (where they existed) looked a little too askance to me. The elevation, and the number of obstructions, increases as you move west from the gulf.
Still, my sightlines are not quite right ... I think it could be because (1) I am wrong with my of estimate of vehicle placement, and/or (2) the area has changed (e.g., trees, construction, etc.,) in 60+ years and there may now something right where all the illustration sightlines/elevations would work.
Did you come up with a potential location that is NOT southwest of Percé Rock? Love to see it.
Surely, with enough digital playing around, better map photos that more closely match the illustration are possible. It is also possible the illustrator took a little artistic license, which is common, meaning you'll never quite get the sightlines to work out.
Following is (red square pic area is rock and greater Percé area) a larger perspective of the entire area.