Here's what to do if you want to get a lift from a Vogon: Forget it. They are one of the most unpleasant races in the galaxy. Not actually evil, but bad tempered, bureaucratic, officious and callous. They wouldn't even lift a finger to save their own grandmothers from the ravenous Bugblatter Beast of Traal without orders signed in triplicate, sent in, sent back, queried, lost, found, subjected to public enquiry, lost again, and finally buried in soft peat for three months and recycled as firelighters. The best way to get a drink out of a Vogon is stick your finger down his throat, and the best way to irritate him is to feed his grandmother to the ravenous Bugblatter Beast of Traal.
Most of the Vogons that appear in the series work in the Vogon Constructor Fleet, a job which allows them a socially-acceptable way to spend their time demolishing things. The captain of the destructor fleet is Prostetnic Vogon Jeltz, author of the poem linked below. And, yes, they are green.