It also needed to look aesthetically pleasing so I decided aluminium and wood should look fine. After a few hours of work and a little frustration I ended up with a nice looking holder. The difficult part was getting the bends on the aluminum correct and also the spacing between each face. The wooden pieces that clamp the Ipod also took some time and skill to make but work very well. There is very little pressure on the Ipod casing itself, the aluminium is easily "tunable" to give the right amount of pressure. Once fastened in the car, the main part can be removed easily when not in use.
Holder can also swivel on two axis making it convenient for listening to music or for a passenger to watch videos. Ipod is plugged into the stereo in jack on car radio unit.
Ipod is now safe to use whilst driving and I am very happy with it.