Where isn't there rust on convertible challengers?
Once I had mine media blasted it seemed to have more rust than good sheet metal. Mine was a New England car so that may explain its condition. But to answer your question, the trunk, the floors, both quarters, the rear frame rails, door hinges, and hood hinges, all seem to be pretty common depending on the overall care of the car. In addition to all that, the previous owner of mine let battery acid basically eat away the inner fender well.
This one may never see the road again.