This was fairly straightforward in Debian, however I'm having challenges with FreeBSD. It looks like a group and permissions issue. In Debian, I simply created a group "vboxsf", added my unprivileged user to it, chgrp the mount folder and then mounted. I tried this in FreeBSD I used this procedure, however the group gets changed on the folder to "wheel" after mounting the shared folder.
Your guidance appreciated.
$ mkdir /mnt/srcr $ ls -ld /mnt/srcr drwxr-xr-x 2 root vboxsf 512 Nov 6 00:03 /mnt/srcr $ sudo mount -t vboxvfs Source /mnt/srcr $ ls -ld /mnt/srcr drwxr-xr-x 1 root wheel 576 Oct 14 21:45 /mnt/srcr $ whoami np $ pwd /mnt/srcr $ ls /mnt/src drwx------ 10 root wheel 320 Oct 14 21:35 X/ $ ls /mnt/src/X ls: X/: Permission denied