An increasing number of car drivers share access to a car by means of carsharing schemes. The use of carsharing has been found to reduce the number of cars, kilometers driven per person, and emissions. Although carsharing is growing, it plays only a minor role in the overall mobility system serving a particular niche of users. Governments, companies and other actors are searching for ways to scale up carsharing. To investigate which policy measures and measures taken by industry actors, are perceived to be both feasible and effective, we discussed a list of such measures during an expert workshop and follow-up interviews with various stakeholders from government, the automotive sector and consultancies. The results show that measures supporting the carsharing niche to grow incrementally are evaluated as feasible and desirable while more disruptive, potentially-higher impact measures changing the car ownership regime are less popular across the consulted stakeholder groups.