Car sharing is an important element of sharing economy, which is becoming more and more widespread in the world. Therefore, service providers would like to expand their capacities and market shares by adding new car sharing stations. In this study, a new model is proposed to provide a simple approach to evaluate potential car sharing stations for site selection problem. A Weighted Aggregated Sum Product Assessment (WASPAS) based Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) with interval type-2 fuzzy multi-criteria decision making (MCDM) model is proposed. Interval type-2 fuzzy sets (IT2FS) are used to better address uncertainty in describing membership and non-membership functions. The proposed method is utilized in a case study of Istanbul, which involves determining the best location for a new car-sharing station among four alternatives. The method provides a more accurate decision-making tool for problems involving high levels of uncertainty.