Probably most other people already did this but this is a new (to me) van.
The original RT back seats were designed awfully. We did a summer cruise through New England with another couple and the wives were troopers but their butts hurt from bad seats.
I found a place online and ordered new ones. They were a little larger and I had to weld up some rail extensions so they could be pulled forward more and recline.
Overall pretty simple. less than 4 hrs work from removal of the old to finish wiring of the seat heaters. You know, Happy wives, happy lives.
This should keep them comfy for the next trip to the Finger lakes and Niagara.