In DVD releases today are 2 films that do a good job helping the viewer get inside the characters.
All in all, Sideways is a wonderful film. Great writing, great acting, and characters with dimension. Some of them you may not like, but you understand them. Payne uses techniques that help us. There is a scene where the characters are drinking, that is shot all wobbly and out of focus, and then you realize he's trying to make you feel drunk to empathize with the character.
In Spanglish one of the characters speaks Spanish most of the time and there are no subtitles. I think this is done so the audience will experience the frustration of the non-Spanish speaking characters that can't understand her ..... very effective!!