First of all, be sure to find out what the laws in your state are regarding carrying in your car. For those of us with concealed carry permits, it is not an issue. Without a permit in FL, you are still allowed to carry a weapon in your vehicle. It must be in a snapped holster inside an enclosed compartment. This is based off the actual law rather than the supposed "3 Step Rule".
I used to have a Volvo 850 which had a center console the perfect size to fit my Glock 26. I could go from both hand on the wheel to drawn and ready in under a second and a half. I actually did it once when some idiot ran up to my window late at night. He claimed to be messing around and went on about some story about being drunk and getting thrown out of a bar. Whatever. I had it at low ready rather than pointing it straight at him, but I made sure he knew I was armed. Nothing happend but I'm glad I was prepared just in case.
One bit of advice when dealing with people that close to your car (for righties anyways). I kept my gun to the right of the steering wheel to prevent a gun grab. All I had to do was turn the gun to shoot. If I stuck the gun out the window or brought it up to the window, the person could have grabbed the gun or at least pushed it down so I would have to shoot through the door. Since you are a lefty, this probably doesn't apply to you. Maybe that is why lefties have a shorter life expectancy?
The center console of the car I have now can't hold anything bigger than my Beretta Tomcat. I don't consider that enough gun so I still have my trusty Glock 26 but I keep it in the door pocket. I have my sunglass case in there to fill in the space and keep the gun from sliding around. It is not as quick as the center console and I have to switch hands but I have got it down to about 2.5 seconds.
This might sound kind of silly but you could do what I do when I am driving through the really bad parts of town. Just drive with the gun in your hand but keep it out of sight. Either that or don't drive through bad areas!
The most important thing to remember is situational awareness. Constantly scan your surroundings for potential threats. Don't stop too close to the car in front of you to allow yourself a way out in case the passengers of the car in front of you attempt a car jacking. You do not want to get in a fire fight in your car. There is little coverage, you have almost no mobility if your car is blocked, you will most likely have barriers to penetrate (windows which will spider once you shoot through it and further obscure you vision), and the noise will be pretty harsh due to the small enclosed space.
Oe last thing... Don't drive like an ass. You will have a lot less chances of encountering road rage. Take it from me. I live in Miami where we have had more than our fair share of car jackings and where we have plenty of road rage. Either that or buy a
bullet proof car!