Wednesday, December 2, 2009 8:16:15 PM
I actually used the spinning thingy for level 30.
Set on the bottom right leg of the top structure, plus the inside beams at the top. Then just the bottom left leg of the bottom structure.
Blow the first charge just as the spinny thing is passing the shadow and then, as soon as the "car" goes into the spinning thing, blow the next two charges to keep the rubble from taking out the bottom tower.
Once that car lands on the bottom tower, blow the last charge.