Parked vehicles can be directly affected by the floods and at a certain flow velocity and depth, vehicles can be easily swept away. Therefore, studying flooded vehicles stability limits is required. Herein, an attempt has been done to assess numerically the floating instability mode of a small passenger car with a scaled-down ratio of 1:10 using FLOW-3D. The 3D car model was placed inside a closed box and the six degrees of freedom numerical simulation was conducted. Later, numerical results validated experimentally and analytically. Results showed that buoyancy depths were 3.6 and 3.8 cm numerically and experimentally, respectively with a percentage difference of 5.4. Further, the buoyancy forces were 8.95 N and 8.97 N numerically and analytically, respectively with a percentage difference of 0.2. With this small difference, it can be concluded that the numerical modeling for such cases using FLOW-3D software can give an acceptable prediction on the vehicle stability limits. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2021.