The study investigates basically, the electric field distribution in a semi-closed region. Specifically, the present work focuses on the electromagnetic wave diffraction at 3.5 GHz in the vicinity of a car where two humans are located inside. The car is modeled as the perfect electric conducting object whereas the human bodies are assumed to be homogeneous lossy dielectrics. To obtain field distributions for different sceneries, the Method of Auxiliary Sources (MAS) is employed. To achieve this goal, the auxiliary sources due to each obstacle are distributed over the corresponding surface element. In the present study, two main different scenarios are considered. One or two cellphones as the source of electromagnetic waves are considered. These cellphones are operating at the proposed 5G frequency band in the European Zone. In this frequency range, the resonances are observed at 3.5 GHz which is in the range of a planned 5G communication frequency band. The present study aims to obtain quantitative and qualitative results for a better understanding of 5G healthy issues. Therefore, as a frontier study, the specific absorption rate (SAR) values are examined for the first time to answer some important questions related to 5G. For such a scenario, MAS is a very efficient, fast, and trustworthy approach to obtain field distribution at semi-closed regions.