I'm still working on modifying my old faceplate so that it sits over the AVIC D3 without arousing undue suspicion. In the meantime, I've got a tip that might work "in a pinch" if you find you have to leave your car parked somewhere and don't feel too comfortable about your aftermarket Nav system sitting in plain view. Print out a "google map" or a "yahoo map" or some other internet map route and scotch tape it to your dash covering up your Nav system. The idea here is to cover up your Nav unit while making it look like you simply taped a map to your dash to make it easier to drive and look at the map at the same time, and you never got around to taking it off.
You could keep a map and a roll of tape in your glove compartment at all times, just in case.
Might work in a pinch. At any rate, it's what I've been doing.
