Occlusion culling.

How would I go about occlusion culling a set of 2.5D rectangles (2D rectangles with 3D transforms applied to them) so that:

1) The quads are rendered in the right order.
2) Quads that intersect other shapes are split into several other shapes that are then ordered.

Essentially, I'm looking to a solution to this (https://bugzilla.mozilla.org/show_bug.cgi?id=689498) but for an unrelated question.

Asked this on SO a while ago but didn't really get a satisfactory answer in terms of an actual, acceptable algorithm: http://stackoverflow.com/questions/16582320/occlusion-culling-3d-transformed-2d-rectangles

>>27
They gassed us hard,
They gassed us long,
They gassed us in our sleep,
They gassed my entire family,
Until there was no peep!
They gassed us day by day by day,
Oy vey, oy vey, oy vey!
Some filthy goyim say,
The shoah was a lie.
But my friend,
I think you’ll find,
It was real in my mind!