I think
@Anthony Murphy has hit the nail on the head here.
VW's privacy glass offering is a Green Tint according to the configurator.
I have read that the bit behind the wardrobe is black but I'm not getting that impression from photo's or VW claims.
In summary I think,
1) the perception of the tint % being less than some manufacturers may be down to it being green.
2) the reflections in the double glazing are different than single glazed sections in a lot of lighting conditions, which is clear to see in a lot of photos. But thats what it is mostly....a different reflection not a tint % difference. Your ability to see beyond it (in to the van) will surely not be more than the other sections. In fact 2 lots of X% because it's double glazed will be darker right? so have they halved it on each sheet for the double glazed bits during production or is the tint 2 lots of X ?
3) Any interior film added to the accessible windows is unlikely to match the non accessible green one behind the wardrobe even if it somehow appears to even up the appearance. So that will be about choice and experimentation with film and I'm sure there are different results out there.
Is it all opinion or does anyone know? happy to learn more before my Cali arrives (plenty of time
).