Mounting on the roof might be ok, but could be distracting reaching and looking up like that.
I mounted the bases to my rigs in the rear storage unit (r/r cargo area) and ran the remote faces to the front. I didn't want the bases to get in the way. I ran 10ga wire from the battery back to a rigrunner power dist block.
IC-2720 and 706MKIIg
I fabbed a mount out of aluminum and secured it to the underside of the center console plate. Rock solid and still easy to get to the controls. Just an idea.
Icom install pics
