#Harrison15 :
My advice: Especially for things other than windows, don't bother using 2 sided. Use a 1-sided material, copy the part & reverse the normals. That will probably give you a bigger file size, but it also has the added bonus of making sure the faces are all valid if you ever have to re-import the SCX.
I suppose this is what you need to do with 3dmax 2010 etc exporter for SLR Then.. if it doesn't support 2-sided, you'll need to copy your mesh, flip the normals(in the modifiers) and that should be it.. ish
