mine would have to have the extra slat as well, regardless if my deck lid could potentially hit them. it just doesnt look "finished" or duster/dart sport specific without it. i would love to see a rear quarter window louver to match, kind of like what was on the 70s cobra mustangs. it seems to me with the materials and some time, you could just start with a frame built to the inside trim dimensions of a duster/DS rear window, and build it up from there. you could use some kind of "clips" to slide it under the window trim up top, and some sort of lock/clip on the bottom for removal, and to give it smooth uninterrupted transition from louver to trim to body. somewhere i saw a pic of ABS plastic / injection mold louvers for 71-74 B bodies that actually looked pretty nice and smooth, and a great fit. allBdamned if i can find it now....personally, im not looking for an exact reproduction of an original part, but more along the lines of something that fits really well and looks good.