Jensen Indash video bypass

I have a Jensen VM9510TS DVD reciver and there is the wire that goes to the parking brake that goes to ground but there is also a GREEN/ White wire that should be hooked up to reverse so if I am useing a back up camera it will override the safety switch. My question is if I do not use a camera do i still need to hook up the GREEN/ white wire ? It shows that wire as + positive.  Also is there a way to bypass the safety switch all together so the kids can watch while im driving?  

                                          Thanks 

That sounds easy enough. thank you for the quick reply