As a guest there are things you have to do to get ready for an event. Showering, making sure you have a clean outfit, breaking in new shoes, wrapping a gift (if you're attending a gift giving event), and yes, making sure you have transportation to the event. Someone calling me to ask for a lift the day of the party is the same to me as someone calling to ask if I'd mind ironing their shirt before the party.
Now, I have had friends ask me weeks ahead of time if I knew anyone also attending the party they might be able to carpool with. Sometimes then I might make a phone call or two to find out if someone would be willing to carpool. Usually in my group of friends it isn't a problem as long as you pitch in for gas.
And once, and I do mean once, a very close friend called me the morning of the party to tell me she was having car problems and she wasn't sure she could make it. I offered to come pick her up when I was going to be in her area well before the party, in exchange she helped out a lot with set up of the party and got a lift home with another friend. Again, once, for a very, very close friend who was very grateful. And I offered. She wasn't hinting or asking, she was simply letting me know so I wouldn't be expecting her.
But in general if I get a come and get me call, nope. You're a grown up, you have to figure out how to get here. You get to work and to the grocery store, you get to bars and clubs, obviously you've figured something out. If it's consonantly bumming rides then you really need a new system. I also don't respond to hinting "Well gee, my car is acting funny and I'm not sure if I can make it...", "Oh, really, well I understand, car problems are such a pain. If you can still make it great! But I understand if you can't" and then I go on with my life. I don't do hinting. You're a grown up, tell me what you need. If you don't want to tell me because you think I'll say no, then deal with the no, or don't bother asking/hinting at all.