I was looking on ebay and saw OEM rear view cameras and some mirrors with the monitors in them. I have an 08 Expo EL Eddie Bauer. Does anyone know it the truck is prewired for the camera if I purchased the OEM camera off ebay could I just plug it in and it work? With that does my existing mirror have the monitor already or would I need a new mirror with monitor? I looked at another Expo with the camera/monitor and saw no difference in my mirror and the one that did have monitor???