If you go to the Volkswagen AutoMuseum and fill-in their Certificate Generator (oh, and remit 35 Euros), they will research your little hobby car, and send you a birth certificate that tells when your car was made, where is was shipped, and what options were included.
More info can be found in this thread at TheSamba.com
Is it really necessary (and worth the money)? Maybe not. Depends on how much you want to know about your car, its history, and its original color-scheme/engine/configuration/etc. Since I want to try and keep it original, I’m curious to see if there’s something about Beevis that I don’t already know.