You can with a mod. Check out the forums at Toyotanation.com. http://www.toyotanation.com/forum/1...8-2013/429729-turn-backup-camera-display.html There is also a youtube video where a guy throws his Tundra into reverse while driving forward and the camera comes on but the vehicle doesn't go into reverse, supposedly some computer protection prevents it, but I wouldn't recommend doing that.
There is this, but $400 bucks seems a bit much. Lots of cool functions, but not sure I want anything beside the nav entry in motion and the anytime camera