I recently discovered something about 3d DWG import. Since there are no import options for DWG files (Assumption is the DWG file is 2d I guess) importing a 3D DWG is a "you get what you get" scenerio. If there's missing geometry you can do one of 2 things. 1- live with the missing geometry or 2-rebuild the missing geometry. The discovery I made, by accident, was the options for .SAT files work on 3d DWG files. When the original 3d DWG file was imported it was missing geometry. I also had a .SAT file of the same DWG file. Using the import options for .SAT and turning on the B-REP Mapping option the .SAT file imported completely. No missing geometry. I left the B-REP Mapping option on and tried the 3d DWG file and it opened completely, no missing geometry. So the enhancement we need for 3D DWG file is the same as .SAT files.