ckbshl – Checking the car door lock (and, for that matter, opening the car door for a girl), are not things that are common decency manners that you would just do for anyone. I would not feel the need to open a door for my friend who was getting into the car for me to drive him to a baseball game. Yet I absolutely do it for a girl who I am taking on a date. This has nothing to do with manners and being considerate. Trust me, the girl is perfectly capable of opening the door for herself. I do it because it is chivalrous! That chivalry does not apply the other way around. manners do.
PS – if I were in a passenger seat of a car with no power locks with my friend getting in and my friend would have to reach for the key to open it I probably would open it from the inside. However, this does not apply as much to a girl in the passenger seat on a date since she may feel too reserved to reach over. Why is that? I think it is since in the heat of the moment, we can expect a girl to be reserved. I think it’s actually attractive if her middos check out. makes me more confident in her natural tznius.