I've been successful importing any kind of data from Autocad. You must
create a .DXF file format (a sort of ascii file) in the Cad enviromment
(use the comand dxfout). To import it into the Grass you must use the
command v.in.dxf.
You can use v.in.dxf just to import data as lines and areas. If you
need to import sites files as well, you must generate an ascii file
just if the data (without any header) and follow the format described
in the manual (the Grass command to import site files is s.in.ascii).
Regards
Roberto de Souza
Research Student
Open University
Milton keynes - England