Just one point before we all go drilling holes out.
Sometime back before the site revamp I posted an alternative window fix that didn't require any drilling holes or bending runners etc.
Assuming the window mechanism on US versions is the same as the Japanese the following should work.
Having removed the door panel.
When looking at the lifting mechanism you need to feel (or look with a mirror) for the fixing screws that hold the window mounting bracket to the lift mechanism. On my VX these screws are in slots and my window was all the way back (towards the door pillar) in them, therefore the window fell forwards when it moved up.
I undid the screws pushed the window and mount backwards and tightened them up, it gave about 1/2" of movement. This was enough to balance my window and make it run up and down with out a problem, and that was 6 months ago.

There is a chance you don't have the slots but I think it's worth looking before drilling.

Col