I just thought of a good resource for you about dating the car (the most likely way to place the photo in time) - Harrah's automobile collection. They maintain a MASSIVE library which covers just about every known make and model of car ever produced, and has documentation of every car in the collection that they've restored, throughout the restoration process. Contact them through their website- http://www.automuseum.org/ . I can say definitively that the photo was taken a number of years after the car was made (probably at least five to ten years) due to the condition of the convertible top. Whatever the car is, it was a pretty nice car because of the S-irons on the sides of the convertible top- those were luxury touches. If it is an American car, it is probably something like a Buick, Olds, Caddy, Lincoln, maybe a Packard or Chrysler. Not later than 1932 or 1933. Most likely late 1920s. I'd email the photo to the Harrah's research librarians and see what they can come up with.