Influence on Bonnie & Clyde?

Does anyone know if Arthur Penn and/or Warren Beatty saw Cul-de-Sac before or during the making of Bonnie & Clyde?
Both films juxtapose laughter/fun and violence/disturbing material. The main male/female couple in each film has an unconventional relationship. Both films are bold in their manipulation of audience reactions.
In short I think both broke new ground and had quite an impact, in different ways.