This project aims to understand the conditions that support the upscaling of car sharing and the role of current and prospective business models play in this process. We will analyse statistically the willingness to share through questionnaire data and the adoption of cars haring services through car location neighbourhood data. We also investigate two case studies. One focuses on demand, and specifically user-producer interaction and pervasive communication in a large scale car sharing experiment in The Netherlands. The other case study will focus on supply side conditions, looking at new business model development at incumbent's companies in the lease car market, as potential new entrants in the daily car sharing market. The proposal directly links to the call Sustainable Business Models, car sharing being a prime example. We envisage that the insights from our research can be used by those having an interest in upscaling car sharing using different business models, including car sharing organizations and other players in the wider mobility market, and by policymakers at local, national and international levels. The project concerns a four-year PhD-project supervised at the Innovation Studies group in Utrecht University, and in close collaboration with experts from business administration, political science and pervasive communication from other Dutch universities. The project is further guided by a scientific advisory panel with international car sharing experts from the US and Switzerland, and by a national stakeholder panel including, among others, the Netherlands Ministry of Infrastructure and Environment, the national traveller's organization and a knowledge platform for the sharing economy.