To set up autofs with sshfs so that it works with your ssh-agent, you need to set your ssh-agent to use a pre-defined path, and then tell autofs about it.

1. Fix your shell. For bash, do something like:

   file.exists() { test -e "$1" ; }
   export SSH_AUTH_SOCK="${HOME}/.ssh/agent"
   ssh_agent_check() {
   	ssh_agent=$(ssh-add -l 2>&1)
   	no_identities="The agent has no identities."
   	no_agent="Could not open a connection to your authentication agent."
   	[[ "${ssh_agent}" = "$no_agent" ]] && { 
   		file.exists ${SSH_AUTH_SOCK} && { 
   			killall -9 ssh-agent 2>/dev/null
   			command rm ${SSH_AUTH_SOCK} 2>/dev/null
   		}
   		ssh-agent -a ${SSH_AUTH_SOCK} >/dev/null
   	}
   	ssh_agent=$(ssh-add -l 2>&1)
   	[[ "${ssh_agent}" = "${no_identities}" ]] && { 
   		ssh-add
   	}
   }
   ssh() { ssh_agent_check; command ssh "$@"; }
   scp() { ssh_agent_check; command scp "$@"; }
   

2. Add the environment to /etc/conf.d/autofs, where $HOME is your home, not root's.

   export SSH_AUTH_SOCK="${HOME}/.ssh/agent"
   

3. Set up /etc/autofs/auto.master like everyone tells you on the internet, replacing $MNT with where you want all the sshfs mounts to live (I use /n), $UID = your UID, $GID ....

   /$MNT /etc/autofs/auto.sshfs uid=$UID,gid=$GID,--timeout=30
   

4. Set up /etc/autofs/auto.sshfs also like everyone says, changing $USER and $HOST

   haller.ws    -fstype=fuse,rw,allow_other,IdentityFile=/home/$USER/.ssh/id_dsa,Port=22 :sshfs\#$USER@$HOST\:/
   

That's it. $( /etc/rc.d/autofs restart ) and you should should be good to go. Otherwise, add verbose to your /etc/conf.d/autofs daemonoptions. ;)

You might be able to get away with running autofs from one's xinitrc, so that would inherit the SSH_AUTH_SOCK and you might not need to use a predefined SSH_AUTH_SOCK.