Bochur, you are right that SOME things are generational. Good manners however, are not one of those things. Derech Eretz kadma l’Torah, don’t forget. Those girls who say they don’t care, have most likely been brought up without certain social niceties and courtesies. They are likely to be the types of girls who think there is nothing wrong with yapping on their cell phones in a restaurant, or that it’s fine to allow their toddlers to run amok in public places, while they sit and chat with friends.
You’re right, I am in my 50s, but that has nothing to do with the expectation that a boy should treat a girl with thoughtfulness on their date. My Rov ZT”L was a European Rov. I never saw him fail to open the door for his Rebbetzin when I was in their presence. If you think good manners ever go out of fashion, then you should think twice. And so should the girl, because they are losing out by lowering their expectations for their dates ( and potentially future husbands)to treat them with courtesy. Women have gotten used to men being crass and thoughtless, and some girls are just immature and clueless today and think the BOYS will not like them if they expect the boys to be more thoughtful.
I HAVE spoken to many young women about this; to the daughters of my friends, to shul members, etc., and the VAST and overwhelming majority of them think that a guy who doesn’t walk them to their door is a jerk. To be fair to you, not all of them agree on the car door issue, but most felt he should at least open the door when they are getting into the car, but not necessarily when they are getting out. I say go for both. It makes you look good, especially if you do it sufficiently quickly and without fanfare, so the girl does not have that awkward “what should I do” moment. And if their MOTHERS know you are courteous, it scores really big points. JMABO (just my ancient bones’ opinion).