1)Always park close.
You want to minimize the amount of time you are vulnerable.
2)Park the car with the front towards the road, so that you can drive away fast if needed.
3)Keep the keys in you hand before you exit the building, you don’t need to stand there like a fool looking for your keys.
A LED light in your car keys can be priceless.
4)Check 360º every few steps, there’s no other way of knowing if you are being followed or ambushed. If you do see a possible threat, you walk back to the building if you can.
5)If the parking lot looks dark, deserted, take no chances. Keep your gun in your hand ( or other weapon) , pressed against your side or concealed under some garment.
Same goes for people with suspicious attitudes, draw slowly and be ready.
A gun already in your hand 2 seconds ( or 2 minutes) before you need it is faster than the fastest speed draw in the planet. Ponder that thought for a second.
6)Keeping a can of pepper spray readily available in the car or better yet, on you, will be very useful in case you need a less than lethal alterative, like dealing with drunk teenagers, upset or disturbed people that behave violently.
7) Finally, a common tactic used by carjackers is to brake the car windows so as to scare you, grab you, and make it hard for you to see.
There’s a polymer film, some call it “anti vandal” sheathing, that sticks to the inside of your windows and not only keeps the glass together but also adds to it’s strength if a stone is thrown at your windshield while driving.
Because of it’s low price vs. the upgrade it means security-wise, this is a must have for your car.
Look around and buy the best product.
I know there’s some of the thicker stuff that makes your windows stop 22LR projectiles.
Not much, but better than nothing, and it might stop other small calibers if they impact in a narrow angle, or deflect. Be advised, this IS NOT bulletproof material, but it does add a bit and every bit counts.