Just found this thread - what a great design/idea.
I found the my axle hitting the wood inner arches within months of picking up my new 4/4. I trimmed out the recesses to stop the axle hitting the body. Then the prop started rubbing - only when road undulations were taken whilst accelerating - didn't have much luck curing that - tried trimming the metal on the tunnel where it rubbed but that didn't help much. Things improved a bit when I got adjustable dampers and a Panard rod fitted - bottoming out stopped for a while.
However still occasionally, with foot down and loaded with 2 people on a full tank it still bottoms out. Worse when the car is driven with enthusiasm, frustrating to say the least. Just about all cars and vans I see in my day job MOT testing have a form of bump stop. Vehicles with leaf springs all seem to. Some are quite battered so obviously come into contact. I'm not surprised to read the comments of those who are lucky enough to have a set fitted to their car - strikes me our cars are crying out for a form of bump stop. I had been trying to cobble something together myself, with no success I'm afraid. Then I found the pictures within this thread.
Wow - really neat - can I have a set please?