I looked a couple weeks ago and couldn't find any good cases.
I thought of one so-so solution you might consider: You can have the dealer deactivate the Power Back Door button on the wireless fob. You'd still be able to use the switch on the dash, the button on the rear door, and the hand's free (foot) sensor - only the button on the fob would be deactivated. (Column "C" means customizable by dealer or possibly 3rd party OBDII hardware like Carista.)
Honestly, how often do you pull out the fob to open the back door? Most times I use the button above the license plate or the "kick" sensor when my hands are full.