Their rear lower quarter patch could use some improvement. I got a rocker, doglegs, and the rear lower quarters, and they do not fit, AT ALL. Reminds me, I still need to do something about that...
Anyway, battery tray as mentioned, maybe the tail light panel under the hatch sill - whatever it is that piece is called. Lower radiator support?
I think the battery tray might be the only piece commonly rusted out they don't make.