OS X also won't allow you to mount another location over one of these protected directories, so there's no way around this. (howtogeek.com)
It is recommended to use the camera's live view while exploring mounting locations. (windowscentral.com)
KidLuf Stroller cup holder — Whether it's for your morning cup of Joe or for the little ones sippy cup, this stroller cup holder gives you an unlimited possibilities of mounting locations. (twiniversity.com)