Chrome OS + VirtualBox Guest Additions

Question

I can't install the VirtualBox Guest Additions in the latest build of Google Chrome OS. When I run the installer, I get the following error:

Verifying archive integrity... All good.
Uncompressing VirtualBox 4.1.8 Guest Additions for Linux.........
VirtualBox Guest Additions installer
mkdir: cannot create directory `/opt/VBoxGuestAdditions-4.1.8': Read-only file system
tar: /opt/VBoxGuestAdditions-4.1.8: Cannot chdir: No such file or directory
tar: Error is not recoverable: exiting now

What do I do now? Can I mount the filesystem in read-write mode? Does the Lime build support the guest additions? I'm using the Vanilla build.

Host OS: Mac OS X Lion (10.7)
Guest OS: Google Chrome OS Vanilla from http://chromeos.hexxeh.net/
VirtualBox version: 4.1.8

Answer 1

So someone on the VirtualBox IRC channel irc://chat.freenode.net/#vbox told me that the guest additions won't work on Chrome OS.

After trying the suggestion from @sarnold, running mount -oremount,rw /, I was told

Unable to determine your Linux distribution