I guess they tried to mimick the real car... that used to 'porpoise' really badly (ie its nose would pitch down then come back up along the straights...) and I'm sure most people will remember the pictures of it at Le Mans when Mark Webber (twice) and Peter Dumbreck's cars flipped at high speed... ouch
Here's a good link to a brief history of Mercedes at Le mans...
Mercedes at Le Mans
