You'd think that the process for installing VMTools on Fedora18 would be the same as 17. But... you'd be wrong.
You'll want to perform all the steps I listed here, but there's one additional step: changing the path for the kernel headers. The vmware-config-tools.pl script finds them in a bogus location, but insists that the path is valid. When that script runs and asks if "" is a valid path, say no and change it to /usr/inc/version/headers.h.
The script will complete and, after a reboot, VMTools will be running and current.