During college years and the reality of being devoid of sufficient income, a few of my old high school pals who rented an apartment together, but were trying to avoid paying a garbage bill, so saved up old Christmas wrappings, wrapped their garbage in it, and placed that on the back seat of a car with the door unlocked. Every day it got stolen.
But just this past month, overseas relatives of an acquaintance of mine arrived in SF, and left their baggage, including some very expensive 35mm camera gear, in a locked car right in front of a Chinatown restaurant just long enough to get themselves on the waiting list - less than 5 minutes unattended. That's all it took. They lost everything.
Even worse, a couple months before, an amateur photographer parked his Lexus over by the shore, and was walking around conspicuously shooting new high-end DLSR gear. That drew thieves to him like moths to a candle. But instead of mugging him, they tailed him a full hour back to his home 60 miles away, and not only took his camera gear, but went inside for an armed robbery, terrifying his family; and then, to add insult to injury, one of them drove off with his Lexus.
As for me, I'd rather look like one of the Beverly Hillbillies instead of looking cool. Or maybe I just look like that anyway. I drive a decently dented and reasonably dirty old truck, and dress accordingly. In any event, it works. But my brother tried to look like a pro, and carried his gear in shiny Halliburton cases, and drove around in a Porche, and had all his gear stolen twice from its trunk.
If I chose to shoot a Leica, I'd put some kind of nondescript relatively ugly wrapping over most of it, and then a dented or tarnished lens hood on the lens.