I was aiming at a fixed compartment box, lockable, where i can leave tool kit,waterproofs,locks(should be on the bike) where i dont have to remember to take a bag and then if i see something i know i can take it home safely.A permantent butperhaps odd looking ,maybe if i get the paint colour near then not so odd, but very practical.
Just buy a topbox and a rack, it'll be a lot easier and less hassle, and you've still got the pillion seat for when you need even more stuff carried!
You, my friend, are cuckoo. PMSL. Backpack?