This research study investigates on the effect of key design variables on adhesively bonded single lap joints and the FE modelling of an aluminum additive manufacturing (AM) automotive joint using commercially available finite element software like HYPERMESH and ABAQUS. The main objective is the realization of a reliable finite element model able to simulate the mechanical behavior of a complex bonded joint configuration, assembled to the structure with injected adhesive in static conditions. The effect of key design variables for Single Lap Joints (SLJs) is analyzed with analytical models like the ones provided by Volkersen and Goland Reissner. Then, the effect of adhesive thickness and overlap length on the overall mechanical properties of the 3D printed aluminum SLJ is discussed by assessing the optimal design choices for the sample automotive bonded joint.