I have a large mottofizz bag im going to be mounting to my rear seat along with my case on the rack. Any tips on strapping this thing down and what works best?
I have the medium one and I use the 4 furnished loop straps with the 2 in front attached to the rear peg hangers and the 2 in the rear attached to a Touratech rack fitted to the rear carrier for more tie down points.
Echoing Electric^^^^ same method I used with my medium bag. A couple pieces of strategically placed blue painters tape will protect the paint from any strap rubs.
At night leave the straps in place and use the 'Fizz cross to keep them tidy.
I keep 2 sets of Rok Straps crossed over my back seat all the time. I almost never carry a pillion, though this setup would be comfortable enough to sit on for a while--if only she (I'd hope it was a she) had a place to put her right foot, since my water jug is there (just out of sight in the pic). But anyhow, there's a world of stuff I can strap down with them, up to and including a very large duffel for camping gear, but also anything the size of a case of beer. Or even Pepsi. This IS my Costco-run vehicle, after all. I don't know how sufficient the Motofizz straps are, but the Rok Straps would be super secure. When not in use, I just cross them over the seat and around the grab bars. Then they meet the stretchy end that's secured to the opposite grab bar.
The X-strap is a great feature--that way you can remove the bag and connect the 4 tie-down straps together with the X-strap on top of the passenger seat when you get to your destination and unload the bike so you don't have to remove the tie-down straps from the bike. If you don't have one I think you can buy it from RiderWearhouse.