I agree... Once you've had the reversing (and surround) camera(s), you'd not want to go back to using only the "neck method" ever again!
Ellmat, it looks as though you're in luck as there seems to be a retrofitting kit; don't know the price in UK though.
See the link to an earlier thread below...
http://f10.5post.com/forums/showthread.php?t=581171