As Dr. Rusty notes, Scared Monkeys has some possible explanations:
1. The US Soldiers are brilliant marksmen by placing multiple bullets through the same hole.
2. The US soldiers are terrible marksmen, firing 300-400 rounds at the automobile and missing a huge percentage of them.
3. She is a lying #$%#$% communist, who has an ax to grind against the US and its Iraqi strategy and is using this to further her own aims.
I'm not at all sure this is the right car, being the third presented by news services as the car Sgrena rode in. There is a seriously fishy smell all over this story. But at least we understand why she didn't tell Coalition forces what she was doing - she thought it was the best way to keep from getting killed (dammit, I can't find the link or remember where I saw it, but apparently she wrote a piece in the past where she explains why it's better to not let the Amreicans know where you are or what you're doing in Iraq - it's safer that way!?!?).
UPDATE: Fixed Scared Monkeys link. Ooops ...