In bad areas, when traveling, and pretty regularly these days, I have a revolver in the same place or under my left leg for the same reason. One of the best OIS shootings we had was a former LAPD bad ass who retried and went to work for us carried a 6" .45 Colt. Tough to draw in the car, so he carried his off duty S&W 669 under his left leg in the car. Whacked a duty with two 147 grain sub-sonics in a very rapid deployment from the car. A ton of my guys (as did I) carried Ruger SP-101's with 180 Black Talons under our legs driving both on and off duty specifically for counter Car-jacking.