His seats still need periodic cleaning. It is my opinion that it is more important to keep modern leather clean than to slop conditioner all over it.
A couple spritzes of the Griot's spray on a leather brush and a quick wipe of any excess will keep them as clean and conditioned as they need to be for the life of the vehicle.
You can get the Chemical Guys leather cleaner and conditioner for $20 off Amazon. Otherwise, you want something with UV inhibitors. Like others say, your leather is coated and conditioners really just sit on top. Whatever you put on it needs to protect that coating.
Just and FYI, you can treat your coated leather (which the vast majority of cars have unless you have a Ferrari etc) just like vinyl....as the coating protect the leather and trying to "condition" it is useless. Like someone mentioned above, I use Leather Masters...works great on coated leather as a "protection", no conditioner that does more harm than good.