Someone modified the "shield" of the otterbox attaching it to some mount. Then clipped the pb in its otterbox into the shield. There is a thread about it somewhere. I think the person even got a second shield from otterbox after explaining the experiment!
I tried the Arkon floor mount and had to return it. The backplate that holds the clips on the top & bottom is not wide enough. The clips are too close together and just barely clear the power and volume buttons. They told me they were working on a new design that was supposed to be available the end of June or early July. I'm still waiting.
This is a RAM Mount i originally purchased for my 11" netbook, but it works perfect for the PB w/Otterbox.
I dont like anything obstructing my windshield and this is totally adjustable for position, angle, height and can be moved to be used by driver or passenger.
I got the RAM mount and added two extra 5" sections and a double ball, rests across the dashboard and down a bit so that top of playbook is level with dashboard. Maybe should have gone with seat bolt mount but this is removable.
My wife said I'll have to be careful if I'm stopped by police they might think all the metalwork is a machine gun!