Mine probably isn't the best solution but it has worked so far. I just took a strip of steel (three actually) and bolted through the floor. Take one piece and connect it to the transmission isolator. Weld bolts (so they won't turn when putting the nuts on) to the other two strips and stick them through the floor. The strips on the inside of the car will help distribute the load on the notoriously rust prone floor. Like I said, it probably isn't the best solution but it works.