 Complete the following phrase:  The McLaren MP4-26 was a Formula One racing car designed by McLaren for the 2011 Formula One season. The chassis was designed by Paddy Lowe, Neil Oatley, Tim Goss, Andrew Bailey and John Iley and was powered by a customer Mercedes-Benz engine. It was driven by Lewis Hamilton and Jenson Button, the and World Drivers Champions, respectively. The car was launched on 4 February at Potsdamer Platz located in Berlin, Germany, shortly after the first test session of the season in Valencia. McLaren test driver Gary Paffett, Lewis Hamilton and Jenson Button drove an interim version of the cars predecessor, the MP4-25 at the first tests to get experience with the final tyre compounds provided by new tyre supplier Pirelli. Right before the 