The car driven by Columbo is a 1959 Peugeot 403 convertible. Only 504 two door convertibles were made in 1959. The original was sold when NBC dropped the series, and a replacement had to be located when ABC resumed production.
Originally, Bing Crosby was offered the role of Columbo. However, citing the fact that he didn't want to commit to a series, he refused the role. He also said, jokingly, that doing the series would interfere with his golf game.