Got weapon, after whack people, if the person doesn't die, you'll be sued and go to jail. If that person died, you become murderer and need to bare the sin for the rest of your life if you never get caught then sentenced to death or jail for 10-20 years. If beh tahan, just ram the car towards the party you wanna whack. Make it looks like accident. Die or no die also never mind, the worst for gagal mengawal kenderaan is a piece of RM300 saman. So what's the point for having weapon in the car? If someone break your window for taking handbag, by the time you get your weapon, he already gone. Further more, if they sibeh tulan, both got down motorbike and attack you then even worst.
If you cannot get real gun (self defense is allowed for those who rich enough to have a gun license), then use your car (unable to control the car and cause accident). Want do, make sure the opposite party die (cannot mark you and revenge). If you don't dare to kill people, then no need to have weapon. Just shout for help or report police. Of cause, as you know the security is not good, need to wake up la. You know people like to pecah cermin, don't la put handbag or expensive stuff just right on top of the seat or any easy expose place. Do risk assessment for every single thing. If you did all your best but still kena, then you can blame the god for so unfair else just like I said, ram them down then reverse and roll few times to make sure they die. After that, straight go traffic police station and report accident. Say you got accident and don't know how the car roll few times. Admit that you didn't wear seat belt and talking on phone.