The plot thickens...
This morning I got the following response from the VCO:
"Thank you for your email.
I had forwarded your enquiry onto our Technical Standards Team and they believe that this category is a typing error as there isn't a Category Z.
DVLA deal with vehicle registration and I would suggest that you can contact them using this link DVLA
https://www.gov.uk/contact-the-dvla. If you have a Certificate of Conformity for the vehicle then the vehicle category should be on this also."
So I contacted the DVLA using their online web chat service, asked what Z1 is and got the following reply after a very long delay:
"I have just asked my support team and they have advised that the category you're seeing will have come off the Type Approval that was provided, it would be best for you to speak with the manufacturer for clarity."
I struggled to understand this. It seemed as if 'Victoria' was suggesting that VW simply came up with the code Z1, and that only they know what it means, and the DVLA don't care because it doesn't matter to them to know what it means.
I asked the person to clarify, 'do you really mean that the DVLA doesn't know what Z1 is, and that it's known only to VW?' To which she replied in a nutshell 'yes' - explaining that it's up to the manufacturer to designate the code...
When I asked how then should a traffic enforcer interpret what Z1 means in terms of road regulations, she completely dodged the question and simply kept telling me to contact the manufacturer.
So I guess I"ll do that - but who would I even reach out to? Certainly the dealers appear to know nothing, so what department should I contact? Anyone have any ideas?
It's all completely bizarre and kafkaesque.