I found these wireless winch remote kit on Ebay from a company called "Winch-It", they seem to have a collection of reasonably priced accessories.
The dual control wireless remote will enable both myself and James (the co-driver!) to operate the winch in a number of situations. Often the person outside the car has a better view of the winch situation so, although I already have dashboard switches fitted, this will give extra capability (and its a bit of a show off as well!)
The kit consists of the receiver that fits inside the solenoid housing on my particular winch along with two remote controls. The receiver is a straight forward fit as it comes with the wire ends terminate with rings that fit onto the screw terminals on the winch solenoid. I simply removed the solenoid cover and attached the leads to the solenoid terminals. A quick play showed that I can control the winch from distances which are too far away to even see whats going on, so it will have more than adequate range on a 4x4 event!