Beneath the rear doors, there is a tubular section of the body, with two holes that hold a plastic plate in place. On my car, these holes allowed water to enter and the outer and upper sections of the tube are completely rusted. I can’t evaluate the inner. Is this an important structural piece? Can I drive it safely with this rust damage?
I would have the vehicle checked by a good mechanic. It sounds like the rust may be so severe that it could impact the integrity of the vehicle. It’s hard to say for sure but it’s worth getting checked out. Your vehicle is a uni-body with a subframe.