vimrc-fu to bootstrap vundle. This code will bootstrap vundle and run PluginInstall when vundle is missing. It is non-interactive thanks to a healthy sprinkling of :silent, and assumes that Git is installed. This version is also aware that it initial run might be under vcsh, so it unsets $GIT_DIR before cloning vundle.

.vimrc

set nocompatible              " be iMproved, required
filetype off                  " required

" set the runtime path to include Vundle and initialize
set rtp+=~/.vim/bundle/Vundle.vim
let s:bootstrap = 0
try
        call vundle#begin()
catch /E117:/
        let s:bootstrap = 1
        silent !mkdir -p ~/.vim/bundle
        silent !unset GIT_DIR && git clone https://github.com/VundleVim/Vundle.vim.git ~/.vim/bundle/Vundle.vim
        redraw!
        call vundle#begin()
endtry
" let Vundle manage Vundle, required
Plugin 'VundleVim/Vundle.vim'

" ... other plugins

" All of your Plugins must be added before the following line
call vundle#end()            " required
if s:bootstrap
        silent PluginInstall
        quit
end
filetype plugin indent on    " required