My Plano in the back of the GQ was $150 odd has the big O ring seal in the lid but doesn't keep dust out which is disappointing given the blurb on them .
The trip were starting next week to the Cape and Kimberly makes me wish I'd looked into yours sooner for the back seat area , seats are removed and have a false floor but making good use of the area would be easier with the expedition box and we've been trialling different methods to make the storage of gear a bit neater and easier to get to .
Will look into it further for next years trip .