Joint ventures do not neccesarily mean joint liabilities, its what is written on the various contracts and agrements that matter, not what is written on the engine.
I thought the claim that a company as large and as reponsible as GM are sticking their heads in the sand over an issue as serious as this as strange to say the least...... a bit of searching turned this up.....
http://vxcorsa-d.co.uk/forums/index.php?topic=447.0
Seems they do care and are doing something about it after all.