I was just looking in your pimpage thread, and I see the shots of your hangers, and it gave me the inititive to code in some submodel detail code. the idea being you make a hanger submodel and it only renderes when you are inside of it, therefore the hanger submodel can be rediculusly over detailed (like 100,000 polys... eh maybe) I also coded in some controle on how it determines when to render the subobject
to activate it, copy and paste this
$detail_box: 1
into the submodel properties feild, the parser for this is realy _realy_ strict (i.e. poorly designed, there must be exactly one space after the colin for example)
(a negitive one should render an object only when you are _not_ inside it's bounding box)
there is also some untested code for added controle over the rendering box, might be fun if it works.
$box_min: min_x ,min_y , min_z
$box_max: max_x ,max_y , max_z
that would be, relitive to the center of the object, how far in x y and z you can go before it stops rendering.
I'm going to look into that nontargetable flag you wanted also, but that deals with with the subsystem code and the targeting code as well as the submodel code (the subsystem code is insane, I've had little experience with the targeting code)
http://freespace.volitionwatch.com/blackwater/fs2_open_r_hang.zip