The IEDs are meant to penetrate the windshield and the shrapnel and 'small balls' coming out the IED are supposed to killed everyone inside. So even if the vehicle isn't much damaged (like the one in the last attack in the video) the folks inside are indeed dead or severely injured. Let's talk about the injuries alone. The PENTAGON said that from the Iraq war at least 400,000 combatants from the occupation coalition got CRITICAL BRAIN DAMAGES!!! That's even worse than death (because they live excruciatingly torturous lives right up to their 'natural death'). These IEDs killed ten's of thousands (mostly contractors) and the US and their allies are hiding the casualties.

If the insurgents plant, say, 10 IEDs...8 are successful.

Iraqi insurgents were masters at IEDs. Especially the Shia groups.