Many types of car crashes can occur on the road. One of the most critical crash types that can happen in the real world is rollover. Unfortunately, analyzing the exact fundamental principle of a rollover incident is difficult and complex. Despite its rise in severity as a serious injury collision, there have been few attempts made to analyze rollover. A stronger vehicle structure corresponds to more efficient protection for the passengers. A two-door coupe or a central pillarless body vehicle can be subject to more severe conditions in the event of a rollover. Reinforcing the side and roof structure of the body is important to secure safety. This paper presents observations from many case studies and actual tests. Central to this paper is an experimental study on the load redistribution effect. A brief overview is given on analyzing roof crush test results, and the optimal structure is investigated in greater detail.