OEM car stereos and in-dash navigation systems typically deter would-be thieves, because these units usually only work in the vehicle in which they ship. A thief would have a harder time selling, for example, a stolen Honda Civic stereo to anyone other than other Honda Civic owners who likely already have Civic stereos! However, in the European market, the popularity of Volkswagen vehicles combined with the modular nature of the manufacturer's infotainment systems makes VW's optional RNS 310 and RNS 510 navigation units prime targets for getting nicked. In reaction to a rash of thefts, VW has come up with an oddball solution to keep users' RNS units in place: the RNS Navi Lock.
The Navi Lock is as simple as it looks. Simply place the panel over the RNS navigation unit, turn and remove the key, and the Navi Lock literally locks the receiver into place. In addition to securing the receiver, the Navi Lock also prevents access to the touch screen, which could be useful for limiting driver distraction. (I know, it's a stretch.)
The lock retails for 219 euros (approx. $287 US) and appears to require the installation of four small nubs around the receiver in order to grip the VW's dashboard.
As security solutions go, the RNS Navi Lock is a bit crude and it's certainly not cheap, but we'd wager that it's effective. The RNS Navi Lock is currently not available in the U.S., but if you're really looking to lock down your navigation system (or really want to prank your VW loving friends), there's always the import option.