Theyre pretty hard to hit. From the Pak36s ive used in sims, and taking at look at them at museums, id imagine a Panhard is pretty darned hard to tag. Plus a Pak36 without APHE, will just go right through. If it doesnt hit a crew member, or the ammo with spall or the shell itself, its not going to stop it. Ive read accounts to the same effect. Meanwhile, it can return fire with a pretty accurate MG being mounted (no recoil), and spray down an ATG. The gunshield is pretty easily penetrated, if you can spot the ATG.
The advantage to an armored car over a light tank or mechanized infantry is cost, road and off road ability. A Panhard is a contemporary of the Pz1 and 2. Its twice as fast offroad. Has the same or better firepower. Has mostly the same armor other than frontally, but is half the cost per unit. Mechanized infantry, true mechanized infantry, is 3-4 years later in technology and operational doctrine. An Sdkfz 251 is going to lose big time against an armored car, and its infantry squad, even with later weaponry like PIATs, Panzerfausts etc, are going to have some serious problems dismounting, then taking on something that already has a bearing on them.
From the sim that had the video I posted. It was pretty easy to get the advantage on a Panzer I, Panzer IIc, Panzer IIIf, and Stug IIIb. Youre faster. Youre smaller. You have a 37mm gun that is just as good as the Pz38(t) (which is your nemesis) L.70 and you have the better offroad ability and higher mounted gun allowing you to remain hull down and keeping everything but your commander/gunner safe.
So what can an AC do that a light tank cant? Change positions rapidly. Adapt to more situations. You get more for the same cost. Fills all the roles a light tank would in addition to what it does better.
And I totally didnt think it was a troll. Thats a legitimate question.