I have the tall bar and luggage rack. The bag has a padded piece that goes down over the passenger backrest and is velcro adjustable, straps on the bottom, and straps on the side. When I get it on there, I can practically pick the friggin bike up by it!

When the top is folded down, it does not stick up much over the backrest. It comes with wheels on the frontside which I removed to get a tighter fit.

Shopped around and got it for $160 off eBay. Looks like the guy I got it from has another up there:

http://cgi.ebay.com/ebaymotors/Harley-KU...sspagenameZWDVW

Check out the dimensions...

"Never underestimate the power of human stupidity" - Robert Heinlein