The Rocket Pooch is a system that combines a titanium cargo cage and a roll-top bag, via a 4-point velcro mounting system. The bag itself has expanding pockets, including a hidden stash compartment inside, and is completely waterproof.
Curve is currently having a pre-order for the Rocket Pooch, with a November delivery. The Rocket Pooch will set you back $229 AUD. Pre-order now at Curve.