I didn't like the way the panniers rattled and moved while I was riding so I came up with this:
Please excuse the poor and dirty photo.
I have mounted another plastic tie-down on the opposite pannier and have tied the two panniers together.
The cable tie setup is temporary and will be replaced with some other slightly stretchy bunjy strap type of idea.
Anyway, it has worked and the bike is nicer to ride with this $1 farkle!