I've owned my Kia for 3 years now, and when I called the dealer to find out how much a transmission/transaxle fluid and filter change would run, he informed me that there is no filter.
I think you're right... After a hundred thousand miles or so, it will be time to rebuild or replace the transmission!
Mark
Its a scam. The no dip stick thing kills me. So even if you trust someone to flush the tranny you can’t even check the color or level. Backin the day you would have to check the level quite often after a flush to get the level just right.