When I swapped out my black for red seat belts, it took me an afternoon to do it. Taking out the rear seats and getting my big butt in there slowed me down. But after all is done I am very happy I did it. I got my OEM belts from a dealer close to me. Fred Beans in Doylestown, PA
BTW I have a black set for sale now if anyone is interested in them. Yes the belts will be different in a charger than a challenger. My Charger has the post for the front seats to attach to. But I would think the rears will be the same.
Matt