I don't have any pictures but it was pretty simple...
- I glued a flat steel weight, borrowed from a cheapy freight car, to the floor of the car.
- I then took a scrap of the light ply from the kit that fit between the walls of the car body and glued the magnet too it.
- Place a paper shim over the steel weight and then stick the wood/magnet assembly wood side down, so the wood is between the magnet and the steel. If you do it the other way, the magnet will usually stick too good and pull away from the wood when trying to take the car back apart.
- Use some slow setting glue place some in the car body sides approx. where the wood will set when the body is mounted on the floor.
- Place the body on the car floor and let dry.
The paper shim is there so that once everything is dry, there is an airgap between the wood and steel plate, allowing the body to snug down farther if need be.
I've used this technique on a few cars but never took pictures.