Some people prefer not to install Drush and its extensions globally. Instead, they keep a copy of Drush and all required extensions per project.
Although the reasoning behind this preference is valid (version fixing of tools and some other reasons), I personally don't like this approach. Just like I don't keep a seperate hammer for every doghouse I build, I don't keep a seperate drush for every Drupal site I build. (No, I never build doghouses.)
This tool implements the 'hammer for every doghouse'-approach. Clone the GitHub
repository (making this clone your Kraftwagen 'tools' directory is very valid
choice) and run setup.sh. It will download Drush and Lenkrad.