Since this thread seems to be dead and people keep asking me to make these things.
Here's my two cents.
IMO,
Your not going to find anyone to do a production run of these things. It would not be economically profitable on such a limited market. The mold to make these would be very complicated and expensive.
A few other problems:
*On our cars, the filler is attached to the body and the bumper is attached to the frame. Keeping in mind that the body of the car sits on big rubber bushings. There would be lots of flex between the two. You would most likely not be able to mount this part to the the bumper for support. straps going to other areas may need to be figured out for structural strength.
*Liability: If someone got into an accident with one of these things, the attorneys would be lined up ten deep to take the case.
*Fitment. The back of the car wouldn't be too bad. Most all the cars that I checked were all with in 1/32" of each other on over all width. The front would be another story. Fender and header panel fitment are all over the place. What would fit on one car, would look like crap on another.
There is a way...
If you really want one. Order fiberglass bumper fillers from me or another vendor. Adjust them to your specific car until your happy with how they fit. Order yourself a set of fiberglass bumpers. Cut them down and "graft" them to your fillers or take it to a body shop to finish, once you feel its beyond your skills.
Where there's a will, there's a way. How bad do you want it?
All I ask is that you post pictures for others who may want to do this.
Mike Barnard