avoid and strong cleaner on it as holden have a history of having shitty leather, especially the coloured leather. using anything strong can get colour transfer to the cloths used to clean it. I like the duragloss leather system from car care products to bring it up to scratch. once its all cleaned up I just use a damp cloth to wipe the leather over each time I wash the car. this avoids the build up of body oils and dirt in the grain of the leather. roughly every month or two I hit it with the conditioner.
another option is to get something like opti-guard leather and vinyl coating applied to it which will help keep the leather clean and need very little maintance