Specialized gun roles make me question the edc choice. If there is need for more rounds, let's just carry and train that way. Not to be snarky, just an observation.
I would second this. When you're in the car the greatest attribute is the ability to get away. Assuming you can't do so, then yes the gun comes into play. But if you're concerned that your daily carry doesn't afford you enough firepower, then maybe you need to reconsider your daily carry? Often people with single stack pistols will say that the capacity is enough for them. Why is it enough on foot, but not in a car? What about reloads?
As a related anecdote, in one course I took a gentleman chose to run it with his S&W Shield. Fair enough, he chose to use for the class what he actually carried. During the drills he would obviously run out long before many others as he only had 3 mags. Towards the end of the day he started getting frustrated with standing around and in his opinion wasting time. The instructor asked him if he felt an attacker would give him the time in the real world to go to the back and reload his mags?