The dirty little secret of the Islamo-fascists is that many of these car bombs are not the suicide sacrifice that they tell of in their recruiting propaganda. All too frequently, the driver of many of these vehicles is unaware that he is doing anything more than smuggling supplies through a checkpoint or planting a car bomb for later detonation. These murderers are often driving not far behind the VBIED with a remote control detonation device. The bomb is detonated as soon as the vehicle gets close enough to the target, or, as in many cases, the device is about to be discovered and the mission compromised at a checkpoint. The checkpoint becomes a target of opportunity, no matter how many innocents are there. We refer to this as a Kervorkian, or an assisted suicide bombing.
As many Vietnam veterans will recall, these tactics have been used before - even the movie "Good Morning, Vietnam" portrayed an attack. I don't recall that suicide (willing or not) played such a big role in those attacks. Given the size of some of these explosions, I gather the bad guys are really getting desparate in trying to sway either the Iraqis or the US to change. I think that ship has sailed, and these attacks can only be irritating the Iraqis. Too bad there's no way to cause these devices to explode during construction so that innocent lives might be spared. It's apparent that the terrorist view of the value of an Iraqi life is not very high.