I had a Dart Sport with the same rear fold down door, I put speakers in but it did limit the door from dropping open all the way. Other than that it worked very well. It was great at the beach, open the trunk and flop the door down...blast it straight out!
I like the clean install of the side panels though...out of the way and clean. A spare set of panels before you cut the originals in case you want to return to stock would be an idea.