"The Day After Tomorrow" (2004)
starring Dennis Quaid, Jake Gyllenhaal
You can read the plot summary here:
You can watch the trailer and film clips by copying and pasting these at YouTube:
The Day After Tomorrow trailer
The day after tomorrow - part 1_12 - Clip.vn.flv
The Day After Tomorrow Torndo Scene
The third will show you a bit of what you describe though it leaves out the car getting flattened, the man and the woman talking, and the man waxing the floors. I still haven't found that whole segment.