The choice of welding process to use should depend on where you have to weld your car, but in general TIG is better for all applications. For aluminum welding, you would ideally only use TIG or GTAW/GMAW with good quality shielding material. For iron body and inconel you want to stick with AC or AC+DC TIG or MMA welding without gas assist, although running out temps are sometimes unavoidable. Make sure when you go for welding the labor should use the best TIG welder. The list of best TIG welders are - https://weldzone.org/best-tig-welder-for-aluminum/
