anyone know what type of setup this is?

On page 36 of the November 2009 Mini Truckin' there is a bag setup with a single bag in the rear! Anyone know about this type of setup?

i know that its a semi air bag. lol. but not sure how the thing works.

cantileaver with a single bag....

i have seen them with forward 4 links as well.

ive had a bag in the center of my rearend before (i was young and trying different stuff out). i didnt like it, made the truck sway and other than looking cool it was a pain in the arse.

with the set-up like in picture... doesn't look like he'd get much sway or side to side when turning.... his canti pivot is a fixed point and theres two points of connection to the axle?????