I know there are a lot of posts on this subject but at the same time there is also a lot of difference of opinions when it comes to range extenders for the P4. Our business relates to supercars and we enter various rally's across the world as well as attending various car related events and as such I am sure a decent range would benefit us from time to time. Is there an overall best piece of kit that everyone agrees on or is it down to choice ? is there a piece of kit that everyone agrees actually works ? Thanks in advance.