this car holder for the n95 was made by using the plastic frame it came with. A simple rubberband is the fixing device here. I glued a thin magnet to the plastic and put the other magnetic counterpart onto a button that doesn't have a function. (I bought the magnetic holder for my old phone - €3.99) I put holes into the plastic for the most used plugs. As you can see the phone doesn't shake or even vibrate. Only my cam movement was a bit shaky. Okay I am cheap.. but this is a working solution until a decent car holder comes out that doesn't cost 50 plus Euros!
here you can see more of how it was done: