Really great to see a Snowpiercer review! Bong Joon-Ho is one of my favourite contemporary directors. Snowpiercer is a modern classic which, like you point out, is gloriously self-aware. Movies that take them far too seriously just come across as cons to me, and I'm unable to engage with them. Bong gets that, and that's what makes his films so exciting - they have so much character and flavour. My only criticism for Snowpiercer is the shoddy CGI.