It does give me an excuse to come up with a way to somewhat secure a long gun in my car, but I'm not sure of a good or relatively convenient way of doing that, and the odds of being able to use it seem pretty small.
Yeah. While it isn't
impossible to come up with a situation where you might
conceivably be able to engage a bad guy with a rifle that was stored in your car trunk, or even one where it might be possible you could get out of (or get TO) your car, open your trunk, get out your rifle, and engage a bad guy, and doing all of that would be more suitable than using the pistol that's on your hip, it does require some
incredibly special and specific circumstances which come up in our society very, VERY rarely.
And it is important to recognize that there are some negatives to overcome: Long guns carried out to cars and placed in trunks every day become quite a hassle. Guns of any sort (whether locked up or not) left in vehicles overnight, and/or always, are stolen quite often and that's somewhere between "a bummer" and "a REALLY BAD THING" depending on your point of view. Guns kept locked down in trunks have to be unlocked to use, thus adding a step to quickly engaging a lethal threat. Long guns cannot be kept loaded in a vehicle in some/many(?) states, thus adding a step to engaging a bad guy and/or requiring storing mags and being able to retrieve them quickly as well.
All of these things are surmountable -- if you really want to. Is it reasonable and workable in the long term to deal with these drawbacks/negatives for the admittedly very small likelihood that you'd ever face a situation where you could and would go get that rifle instead of dealing with whatever it was with the pistol you carry on your person?
I think what this boils down to is the phrase: "If you really want to." We like rifles. We like having them around. We like self-identifying as a rifleman, with his weapon handy, or at least nearby. Carrying an AED is vastly more likely to save lives than any gun we carry, especially that trunk rifle. But amazing medical tech gear like AEDs aren't our area of hobby and interest, so we don't bother. Wearing a hard-hat would be much more likely to prevent our own sudden deaths, but we'd consider anyone who'd do that every day to be a total weirdo. To some extent, it's more engaging to picture ourselves as a hero with a rifle than a hero with a medical kit, or defending ourselves with a firearm than with personal safety gear. (No negativity implied there, that's just how it is.)
There's nothing wrong with that. It's a free country, at least sort of, in most places, and we can carry a rifle in our trunks if we want to.
I personally believe there are very good reasons for trying to understand risks and odds in realistic terms and to only do things
in reaction to those risks and odds if it is reasonable to do so.
So... going back to the OP's question, "In light of recent shootings...", no. I don't think it is reasonable to change anything about my carry gear -- or even if and when I carry a firearm -- in light of those events. I'm certainly not putting a rifle in my vehicle BECAUSE of them.