CO, here is a link to a thread on this:
http://www.groupsrv.com/hobby/post-28101.html
The MDF, wood and other stuff is all mentioned, there is something bad about having the material too hard- ie: not giving to strikes and vibrations or some crap- I really don't care, I don't think anyone cares, I don't even think your "new" garage is real. The situation is so Snuffleluppagus.
Just hurry up with the decision and the damn pictures.
