Intriguing idea. Got me interested so I looked around at retrofit arms. They exist, but there doesn't seem to be much on the net about installing them in a non-standard application. Some scant boating forum entries on retrofit and repair. It sounds like a great idea. I hate driving with my head cocked when the visibility is poor, trying to peek through the tiny area the wipers clear (and that's after I installed civvy wiper arms so I can use modern blades).
I did notice some comments in my search that pantograph arms may need heavy duty wiper motors. I seriously doubt our HMMWV wiper motors are HD. Might have to retrofit a new motor, or a motor per arm...
BDGR