The camera mount is quite nice as I can move it about, I put it behind the mirror so it doesn't get in the way. It is a flex mount though and the phone is heavy so it does bounce a little. I'll see what I can do about it, I may be able to use the mount and anchor it against something with padding to prevent rattles.
Thanks for the tips - any acceleration is only to get it out of the way - less time at lower MPGs, or thats the theory anyway.