^ Good info.... so what was your recommendation?
My seats are filthy too, along with the rest of the interior.
I have some simple green around the house as well as some simple green Aircraft (formulated to be non-corrosive, does not need to be rinsed off metals).
I think from what you're saying above that nothing works so give up and go home... but i'm not sure.
If it is a urethane coating on my 325xi with sport package, then I don't see a problem spraying with simple green, brushing, and rinsing. Is that what you are saying?