Rear of the B pillars the glass could be so dark that you can't see through at all - same rules V8 posted in #10 also apply to after market tints.
My S/B has privacy glass and you can barely see into it under normal light conditions :-
Hope you get it sorted but make sure you get an Audi branded replacement glass and not one made for the replacement market otherwise the trademark will likely be different. Had a new screen on my Leon and all original glass had SEAT on the trademark but the new screen was Pilkington and had a completely different logo/emblem. Prob more difficult to see on privacy glass but thought I'd mention it.
My rear window is nowhere near as dark as that