I hope I am not breaking any forum rules, but I am so delighted with the leather seats installed locally for my 2010 Prius III - that I just HAVE to tell you about it. The company that did it, Auto Editions, did an entirely professional job. The colors match perfectly, there are no loose ends anywhere, everything is neatly stitched, and there are no zippers - rather than stitching - in the rear of the front seat backrests (for a cheap way to get it done ala seatcover style). Included was contrasting armrest leather on the inside of each of the four doors. The original cloth fabric over the seats was removed entirely before installing the leather. I highly recommend them. They are located in Westerville, Ohio (a suburb of Columbus) and can be reached at 614-899-9100. The manager is Dan Montgomery, and his cell phone number is 614-206-3791.
The installer's name, city, and telephone number are contained in my original post in this thread. Just give him a call to get a price.