Perhaps this can do the job. I've got no time to try it now, since it
seems to be too complicated for me to do it on the quick.
"udevil - udevil "mounts and unmounts removable devices [snip] It can
also selectively automatically start applications or execute commands
after mounting [snip]" -
https://wiki.archlinux.org/index.php/Udev#Automounting_udisks_wrappers