I've got a roof rack cargo bag works great once it's set up if you plan to get one couple recommendations. get one thats waterproof NOT water resistant..doesnt help much when you have been traveling over 6 hrs and it's been nothing but rain all the way ..been there..
difference in the two...water resisitant: traveling along and you run into some rain for a couple hours..no problem ..been raining all day...problem
got mine from autoanything.com couple years ago just looked at the site and they dont carry the one i have also get one with plenty of straps to tie down the bugger .
could always look at a hard top carrier they have less room in them but they bolt to the roof rails.
hope this helps