A process of producing a shaped article suitable for use as an automotive body panel intended for finishing by painting and, if necessary, baking. The process comprises obtaining a sheet article made of an aluminum alloy of the 2000 or 6000 series in a T4 or T4P temper and that exhibits an increase in hardness after painting and optionally baking, shaping the sheet article by forming to produce an intermediate shaped article, and subjecting the intermediate shaped article to a thermal spiking treatment prior to painting and optionally baking. The thermal spiking treatment involves heating the intermediate shaped article from ambient temperature to a temperature in a range of 150 to 300 °C with or without holding at that temperature for a period of time to enhance the increase in hardness.