Derek from Touratech confirmed that as well and I ordered the silver locking mounting kit for my bike. Thanks!
I checked the BMW microfiche for a part number for that black plastic piece centered on the handlebars that the Zumo base attaches to and couldn't find anything. I just sent an email to Rose Marston at Max BMW in North Hampton, NH where that piece was installed in March of 2009 when I picked the bike up. I'm sure she'll get back to me with the info and I'll pass that along right away.
Have a great day and ride safely!