What makes you think they are weak? If it's dintability that doesn't surprise me. Their strength is in their structure and choice of materials which can't be seen.
Have a watch of these two.
[ame="http://www.youtube.com/watch?v=k3ygYUYia9I"]YouTube - Fifth Gear Crash-test Volvo 940 estate vs Renault Modus[/ame]
[ame="http://www.youtube.com/watch?v=Ad8dHYAIhZ4"]YouTube - Fifth Gear: 4x4 Crash Test[/ame]

