I've seen pictures of the BigFoot converted Marder, but it is way too expensive!
http://www.rc-car-online.de/bigfoot_eng.html
Instead I am trying to make up some adapters so I can fit some Ofna Monster Pirate wheel/Tyres to my Marder. Have to go from the 17mm hex on the ofna wheels to the square wheel mounts on the Marder.
If anyone knows of some adapters commercially available I would be most interested?