Continuity mistake: When Carrie is trying to hail a cab, you can see her walking down a busy street in NYC. Big's black sedan is nowhere in sight. But a moment later; his black car suddenly pulls over to the curb right behind her, as if it was just next to her in traffic. There was no time for it to have come from anywhere else, or across from a far lane. The car was not further down the street coming towards her either, as you can see from the long shot. Big's sedan was not present in the street, before it pulled to the curb behind her. (00:14:45)
Continuity mistake: When Carrie climbs into Big's car, she puts her bags in first, in between her and him. When the shot changes, a split second later her bags are suddenly tucked down by her legs on her other side. (00:15:15)
Continuity mistake: When Miranda says bye to Steve after he proposes, in the front angle she holds the door from the upper part, but in the angle shot from the side she is holding the middle part.
Audio problem: After Carrie and Miranda are served their drinks and the credits roll, they have small talk about flying to Rio but their lips are not moving or are not in sync.
Continuity mistake: When Carrie gets in Big's car a group of bystanders can't help staring at the shooting of the scene.
Continuity mistake: After Carrie tells Miranda "Now that I'm stuck with the bad ring" there's a wide angle where Miranda's right arm is suddenly raised against her cheek.
Answer: I'm a long-time fan of the show, having re-watched it many times, and I definitely remember slightly different dialogue at the end of that episode than what's on my DVD. I'm afraid I have no idea why this change might have been made or any other info, but you're not insane.
Purple_Girl