This study explores marketing messages promoting sustainable transport and reported motivation to reduce private car use within different segments. A stated preference survey targeting a sample of 1300 residents in Sweden was conducted, and exploratory factor analysis was used to identify underlying dimensions of a set of 19 marketing messages. Self-efficacy and collective efficacy were defined as latent factors, and the latter was found to be a better motivator for all segments. For the most car-advocating segment, however, the factors (both self- and collective efficacy) was unsuccessful in inducing any reported motivation to reduce private car use. Assimilation bias seems to influence the respondent's interpretation of marketing messages.