Thank you all!! Great article RAB. Summary:
• Common for windscreens to help significantly in reducing UV due to being a laminate with a vinyl layer.
• Some windscreens are even more effective by having a layer which polarises the light.
• It is practically possible to retrofit a film that has the same benefit (but may not be permissible if opaque).
• It is less common for side windows to be laminated (normally tempered only) therefore assume less protection.
• Even normal side windows filter some UVB (burn/tan) but not UVA (skin ageing/raised risk skin cancer).
In relation to the A2 in particular I will try to find out if the side glass is laminated (in which case the performance matches the windscreen). If it isn't then a retrofit film is a possibility provided that doesn't impede opening the window.
atb