No, it shows that there are differing opinions and not the ad hom slight you offered to those that think the idea of putting a rifle in your car over some fantasy of fighting terrorists on U.S. soil, much less in your town. Vehicle break ins have been pointed out as a reason to avoid this notion. Friendly fire as a civilian brandishes a rifle is another. Overpenetration, if not outright misses, harming innocent bystanders yet another. Lack of training. Racial bias. Poor judgement and reactions. There are numerous logical reasons that such an idea is at best reckless with no realistic example of a good reason. Walter Mitty fantasies of daring do don't outweigh the reality of all the ways this concept is ill conceived.
A round such as 5.56 does not present a significant difference in over penetration risk compared to a round like 9x19.
Not everybody has a significant training difference between pistols and rifle, for some people 'lack of training' might be a reason to opt for a rifle instead of a pistol, no?
Firearms including rifes can be secured fairy well in vehicles.
Friendly fire is a risk with handguns also.
Racial bias, for those it applies to, is a risk with handguns also.
Poor judgment and reactions are a risk with handguns also.
Brandishing, as a legal term, has a specific meaning (for the states that use that term in their law), and I don't think anybody here is talking about brandishing anything. But even then, you can brandish a handgun if you reach for it every bit as much as you can a rifle.
We have one very well known and publicized example where private citizens with rifles in their car...on a college campus no less.
Outright misses are probably more of a concern for handguns than for rifle given how much more difficult it is to hit a target, all else equal, with a handgun vs a shoulder fired rifle.
The really strong logical reason that a rifle in the car probably won't ever help you is that it is very unlikely you will find yourself in a relevant situation. But then if you carry a gun at all you are already doing so in preparation for a very unlikely scenario.
IMO this comes down to the same old junk we see on gun forums (and in life in general) all the time:
Those who are less prepared than you are sheep/ignorant. Those who are more prepared than you are paranoid/wannabe heroes. Too man people seem to think that their specific level of preparation is THE correct one and everybody else is wrong.
That's why so many people would say that you, hso, are a walter mitty type fantasizing about playing Hollywood action thriller save the day hero because you carry a handgun.
Some people choose not to own any 'weapons' (defensive tools) at all. Some choose to own one and keep it only in their house. Some only in their house or their car. Some carry one on their person. Some carry a spare mag also. Some carry a backup gun. Some carry a rifle in their car. Some might carry body armour. Some might regularly wear body armour. We need to stop talking like the anti and we need to top proclaiming that somebody who prepares for more than us is some paranoid fantasizing nutcase.