ok so i have a 2001 disco with the alpine system and 6 disc changer- BUT i was curious if land rover ever made this truck with a navigation system and if so- where can i go to buy one of these units? anywhere on the web... i really dont want 2 get a flip out aftermarket screen as i have had 1 of those in my show truck and don't like it... any sites on the net that sell the navigation unit?