Indeed. It's always good to have something powerful on hand, just in case you have to defeat something heavily armoured. Of course, in the early game you have very little powerful weapons anyway. Aside from the assault cannon, early game guns are basically useless against armoured cars.
... However, I just had a fairly early encounter with armoured cars myself in a pogrom in the second month. There were two cars, and I spent a lot of the mission hoping like hell that they wouldn't open my airbus' doors. (Fortunately they didn't!) I used a frag grenade and a couple of molotovs to soften them up, and finished them off with an axe. The axe or the hammer in the hands of a reasonably strong gal can beat a car in around 5 swings. (That means probably not in a single turn - so have an escape plan!)
So, the early game options for beating a car are: assault cannon; axe; hammer; weapons found from enemies.