Where was Grand Highway filmed?

1987 French film directed by Jean-Loup Hubert

Grand Highway (1987) was filmed in Rouans and Acheneau, 2 places named in its Wikipedia article, in France. Wikidata records no filming location for it at all, so the article is the only recorded source. Each place says where its claim comes from.

See them on the map → Wikipedia Source data

Places per Wikipedia's article

The Wikipedia article names 2 places. Each links to the sentence that says so.