Well, I'm not raising my voice or being picky or anything here, but that site can hardly be used to prove anything. The topic is about the Chinese way of copying everything (including the BMW X5 - that's a Chinese copy in the first picture), and a translation of the text above the first Lada pic says something like: "But before we laugh at the Chinese - compare the Buick Sail (for the Chinese market) and the Lada Kalina (for the Russian market). (...) Who are more skilled in thieves' craft?"
Which definitely does not prove that there is any GM involvement in the Kalina - it actually seems to point in the opposite direction: That the Kalina is a copy. And if you look at it, that seems more likely: The roofline isn't quite the same, and the A pillars and doors are also clearly different - and these are all structural elements. To top it all off, the Sail (which is now marketed as a Chevrolet) is 10 cm (4 in) longer than the Lada, whereas the Lada is 10 cm wider. And the wheelbase doesn't match, either...
Conclusive?
(No, I'm not a lawyer and have never dreamt of being one. But this was quite fun
)
Please tell me if you still disagree. I could still be wrong.