I've been searching sporadically and not with much details.
BUT, what I do remember is that you need some china-made aftermarket module and some work with the wiring.
If I'm not mistaken, auto up/down buttons have two positions in both ways: manual down, auto down, manual up, auto up.
With this module you lose the option of 'manual' functions.
It does appear attractive to have those options, but they're not factory originals so I always kind of stay away.
While on the subject, it does annoy me HY didn't put auto up function at least for the drivers window!
Here's an example: hard rain, a bunch of cars behind , shopping center ramp without roof, something ahead of you that requires some maneouver, but you have to keep your finger on the bloody button or you're all drenched!