So the back part between the backseat and the rear windshield in my car (sedan) was shaking like hell after installing my Type-R 12. I had no idea how to remove the panel, and didn't have any dynamat anyway. So, I put my $120 biology book on it and now the shaking is gone. Hooray for science!
Now, if anyone has any less ghetto ideas for me, please let me know.