Roof rack and cargo box, roof bag or hitch cargo carrier

A customer is on a long road trip with a AeroPACK on his Prius. He is reporting good results. I will post more info and photos when he has finished the trip.
Mike

 

Two year old thread, but we have a 2010 Prius and we are looking at either a roof rack bag or container. The bags are easier to store and MUCH cheaper. Can anybody speak to one specifically for the Prius; which one do you use and how does it fit? I assume it would knock down mileage quite a bit but it is what it is and we don't own a pickup truck for the occasional time we need some serious capacity.

The hitch is not a bad approach, but for camping we're already using that with a hitch-mounted bike carrier, so really need the roof capacity and the trunk is already full with tent and cooler