A man should always walk a woman to her car. Or to her front door.
If you met up for dinner and you parked outside of the restaurant and she parked a block away or in a parking garage, escort her to her car. I don't care how you get there - if she trusts you, then you can drive her, but otherwise you should walk with her. Whatever you decide is fine, but make sure she's taken care of. If she came over to watch TV, but has to go home that evening, WALK HER TO HER CAR. I don't care if it's summer time and it's still light out, it's the gentlemanly thing to do. The fact of the matter is, it doesn't matter what day it is or even what time of day it is, a man should accompany a lady to her car. ALWAYS. It shows her that you care. Plain and simple. Those little things go a long way. She may tell you she's fine walking by herself, but even if she refuses your offer you should probably still walk with her. She may not be letting you off the hook so much as she may be testing you. Same rules apply when picking her up or dropping her off. Walk up to the door to let her know you're there and walk with her to the door when you leave. You may have that awkward "should I kiss her/does she want to kiss me" moment, but even if all you get is a peck on the cheek, you're still scoring points in the chivalry department. It's a common courtesy and it shows you have manners, which is something that seems to be rare these days.