Three years into this hobby and nobody warned me about unibody rust repair. Body-on-frame cars are forgiving — you can replace sections, weld in patches, and the structural loads are handled by the frame underneath. Unibody cars are different.

Every panel is load-bearing to some degree. The rocker panels, the floor, the firewall — they all contribute to the car's torsional rigidity. When those panels rust through and you weld in replacements, you have to think about fit, alignment, and how the car will behave.

I've done two Mustangs and a 240Z. The Mustangs were more forgiving. The Z was a lesson in patience and precision.