I have a short length of fuel line that I use to remove the cap from the inner dual, then I have one of the rubber valve stem extenders that I screw on from the outer dual. Once I've added the desired amount of air, I remove it and put the cap back on. No worries about the extender coming loose of wearing a hole in the side. For the outer dual, I do have a set of small curved extensions that I found at CW. These could be tightened down with a set of tiny pliers when I initially installed them, the later when I removed the tires for rotation and balancing, I installed the extender on the desired wheel that would end up as the outer dual. That way the balance was done with the extender in place.
I can't believe ford "engineers" put such small holes in these wheels - GM and others including heavy trucks use 2 or 4 large holes that provide access.
