Complex sentence: Heidfeld was disqualified from the European at the Nürburgring for his car being two kilos underweight; at the Austrian Grand Prix when their two drivers crashed into each other, putting them both out of the race.
Split into simpler sentences: Heidfeld was disqualified from the European at the Nürburgring for his car being two kilos underweight. At the Austrian Grand Prix their two drivers crashed into each other, putting them both out of the race.