 Complete the following phrase:  The car underwent an engine change for the 2015 season, changing to an Advanced Engine Research twin-turbo V6. This necessitated extensive revisions to the chassis and as a result the team missed the first two races of the season in order to modify and test the cars. Due to the new AER P60 engine, the car featured a new cooling layout with dual heat exchangers on both sides of the car, a revised transmission, and most noticeably, a distinctive split airbox, located further back on the engine cover compared to that used on the Rebellion-Toyota. The split necessary, due to the airbox being located so far back on the car, that the mandatory fin had to pass through its centre The revised car was tested for the first time at Paul Ricard in France at the end of May and was expected to take part in the 