None survive hard crashes all that well, but you can help extend the life of a shell with a generous layer of shoe goo in the wheel wells and all of the front. To lessen rear body tucks and the damage from them, smear a thick layer of shoe goo in the back corners and in the wing struts. Some people embed drywall tape in the shoegoo.
In my experience, the prettier the paint job, the shorter the life span. Regardless of lightweight vs regular or any other preventative measures I might have tried. The ugliest shells always seem to last the longest.
Smooth wheel well edges will maximize the strength there too. You don't want any jagged cut lines. They will be a weak point where cracks start.