This paper is focused on hybrid busbars, which are crucial elements in modern electric vehicles for distributing electric power to multiple equipment such as the electric motor, the electric power steering unit, and the AC/DC converters. The authors investigate the possibility of replacing fastening by a new joining by forming process to assemble the copper and aluminum conductors of hybrid busbars at ambient temperature. For this purpose, the paper starts by analyzing the influence of the bolts, of their tightening torque and of the sheet surface preparation conditions in current flow and electric resistance of fastened hybrid busbars. Then, the new joining by forming process named ‘injection lap riveting’, with a two-stage fabrication route is introduced, and comparisons are made between the current flow and electric resistance of the two different types of hybrid busbars. Ideal hybrid busbars contact conditions are also replicated in laboratory for further comparison purposes. The investigation combines experimentation and numerical simulation, and results show that the electric performance of injection lap riveted hybrid busbars made from sheets in the as supplied condition is similar to that of fastened hybrid busbars made from sheets with previous surface preparation by grinding. The electric performance of the injection lap riveted hybrid busbars is stable and not compromised by the loosening effects that are commonly experienced by fastened hybrid busbars, which give rise to a significant increase of the electric resistance.