I thought I would quickly publish a little known trick. Since AutoCAD 2004 was released there is no longer the need to install a custom object enabler. Architectural Desktop objects will now display in AutoCAD. However, if your requirements are just to have a flat 2D underlay, then there is a command (ExportToAutoCAD) built-in to the last version of AutoCAD 2006 that enables you to convert the custom objects to plain AutoCAD entities. The command ExportToAutoCAD even contains the Express Tools Flatten and Overkill to clean up the data.
You can use the CUI to add the Toolbar and ExportToAutoCAD command in your AutoCAD 2006.
Load the provided CUI located in C:\Documents and Settings\user\Application Data\Autodesk\AutoCAD 2006\R16.2\enu\Support\AecArchXOE.cui
The added toolbar with the second icon being the ExportToAutoCAD.
You can also use the command or script it from the command line.
File format: 2004
Bind xrefs: Yes
Bind type: Insert
Filename prefix: ACAD-
Export options [Format/Bind/bind Type/Prefix/Suffix/?] <Enter for filename>:
You can easily script the command to batch convert DWG files.
Now I am headed back to Amsterdam to catch a flight back home after a few days here in nice and warm Europe. I had a great time and will publish more photos of my trip after I return home.