Do you lock your car doors while driving?

[TheKitchenWitch]

I've had 2 instances when I've been very glad that I've had the car doors locked late at night, although it's not something I usually do.
I now can't decide whether it's better to have them locked or not.
DH's car has automatic door locking, which makes me think it might be a better idea for some reason?

Mine lock automatically, but in my old car when I had to do it manually I would do it if it was dark or I was in a dodgy area.

Passenger side always stayed locked anyway because I used to just chuck my bag in as I got in!