Jazz Rear swing arms

OK guys i have seen a lot of people buy these Jazz Anti sway bars.
and I'm wandering how it works on the back considering the jazz does'nt have a live axle or independent suspension.
as it is the Jazz has a rear swing arm arrangement. like so (red parts are where its bolted to the chassis, blue squiggles are springs):
http://i1184.photobucket.com/albums/...s/JazzRear.png
Really its already like a anti sway bar, because when one side goes up the other side has to go up as well, the huge hunk of metal under the car isn't going to just let one side go up and the other side stay down.
The whole point of a swing arm is to create torsion with roll, so ie one side goes up causing the bar to twist and turn the other side up. here's another pic (blue is the first force ie hitting a bump and the red is the result of that force)
http://i1184.photobucket.com/albums/...ms/sawybar.png

so really the jazz already has one. You don't need a rear sway bar on there the current setup is already like one, if u want it to roll less on the back then just put on tougher springs, the Ultra racing ones only limit your spring travel, and the new version ones they make don't even mount to the car it just hangs off the springs and run parallel with the already setup swing arm - its literally just there for the ride.


so if someone can clear up where i went wrong it would be great if not then Ultra Racing rear anti sway bars are gimmicks.

I think this guy has a point. Anyone got ideas?

thanks

unfortunately the first model they released of the jazz rear sway bar, they failed to show a picture of one installed on a jazz
http://www.ultraracing.com.my/vgreen...16mm%20old.jpg

but in the new version which is apparently 10% better its not even attached to the chassis and just runs under the original rear swing arm thing.
http://www.ultraracing.com.my/vgreen...rear%20ARB.JPG


I dont want to think that UR is lying, but i also dont want to think that the person who designs these thins is an idiot, or has no knowledge and just designs them for popular cars without thinking or knowing whats underneath the car already.