Don't know about axis Earl, but we put ours on the drop down bed over the captain chairs. Under the matress, don't even know it is there.
Yes, same place as MoMike.... Tried sticking it to the top center of the windshield and other spots and was intermittent reception. Putting it in the middle of the upper bunk seems to do the trick. I have the OnyxPlus which replaced my old XM2Go unit.