I'm trying to add Go language syntax highlighting to VIM on ubuntu with resources and direction supplied here http://go-lang.cat-v.org/text-editors/vim/.

go.vim

Place $GOROOT/misc/vim/syntax/go.vim in ~/.vim/syntax/ and put the following in ~/.vim/ftdetect/go.vim:

au BufRead,BufNewFile *.go set filetype=go

This is more or less the same vein of procedure for customizing vim syntax I've seen elsewhere (Vim 7.3 on Ubuntu 12.10 doesn't have 'ftplugin' directory anywhere and https://github.com/jnwhiteh/vim-golang/blob/master/readme.txt)

So I think I'm doing the right thing when I create directories:
~/.vim
~/.vim/syntax
~/.vim/ftdetect

and follow the above instructions by adding

go.vim to ~/.vim/syntax/ and creating a file, go.vim, in ~/.vim/ftdetect/ which contains

au BufRead,BufNewFile *.go set filetype=go

Yet syntax highlighting does not seem to occur. Is there something I need to do to force VIM to look at these new settings files?