Let the tubbing begin.

They should be able to make you some. The shape of the wheel well is the same, only wider. They would just need to leave extra material on the end when they heat it on the mold to form it. It's worth a shot to ask. Just tell em you need X inches added to each one on the end pointing towards the outside of the car. The cargo floor part will be no different than factory. You'll just have to cut it to fit.