I hope you don't mind me replying to a question posed to Chris..
What I do is shoot a few shots in register, with the polariser in various positions then layer the files up set to darken.
I didn't do any polarization in the shot above but, yeah, I too have done multiple exposures with a polarizer in different rotations to solve multiple angles. That said, I am finding Polarizers less and less usable as the newer, laminated glass designs reveal strange patterning under polarization. I oftentimes just have to put up duvetyne or thick black visqueen to block reflections.
CB