Apparently there is no 19" Cadiz option in the GB because the weight of them takes the car into the next emissions band. In Germany, for example, they have both styles of 19s as an option to the 18s.
Rubbish. We pay car registration tax based on the co2 emissions of the car and there is no mention of an emission change on any brochure or even on the configurator.
I don't understand your post and maybe I didn't make myself clear in mine, so I'll try again. As I understand it 19" Cadiz are not an option in GB because the extra weight of the car caused by the heavier wheels, results in the car having higher emissions, meaning the car falls into the next tax bracket. 19" Pretorias are lighter so the car manages to stay in the same band as a car on 18s. Or all of that could be rubbish and it's just that VW don't provide the 19" Cadiz option to GB customers because they choose not to.
Sorry Trev, I'll try to explain better:
I dont believe the wheel weight theory to be true. My reasoning is that there is no change in claimed emissions on Golf R's in Ireland due to different wheel choices. The emissions level is crucial as the tax on new cars here is based on the CO2 emissions. So if there was any change in emissions due to wheels, it would absolutely have to be declared here, and there is no mention of it on any brochures or the online configurator.
For the actual reason for not offering the wheels...I dont know. VW UK do some strange things with options: Why didnt they offer the alancantara interior? There's cerctainly no weight penalty there as the full leather option is available... But then you guys get a huge standard spec.
EDIT: I have just thought of something else: What mass would the sunroof add to a car? I'd say 15kg is a conservative estimate, which is far more than a set of wheels would ad. There is no emission change in the sunroof case.