Autodesk offers for free to students and educators for one year (renewable). This gives you full access legally.
The 2006 version was defined by "out-of-the-box productivity" and focused on enhancing the tools drafters used most: Autocad 2006 with key full version
"Unlock Your Design Potential: Exploring AutoCAD 2006 with a Full Version" Autodesk offers for free to students and educators
: Although more famously introduced in a more recent version of AutoCAD and other Microsoft Office products, AutoCAD 2006 marked a shift towards more intuitive and easily accessible tooling. Autocad 2006 with key full version
: Allowed users to change the size, shape, or configuration of a block without creating new ones [5].