In case you're wondering, yes, that cushion is the lumbar support. You can also mount this bag in front of the sissy bar and it will provide lumbar support for you. 
This is what I've been looking for, so great vid. There's another one here that shows what I'm talking about:
http://youtu.be/huebFSiQdRo
This is what I've been looking for, so great vid. There's another one here that shows what I'm talking about:http://youtu.be/huebFSiQdRo
