 Complete the following phrase:  After the teams dramatic slump in 2014, the 2015 season marked a small improvement in form. The car was considered an improvement compared to the disastrous Lotus E22, which suffered from reliability issues and struggling for competitiveness due to the underpowered and unreliable Renault power unit and the fundamental flaws of the E22 chassis. However, both driver errors and unreliability cost the team points finishes in many races, limiting the cars potential of consistent points scoring. Maldonado retired in 5 out of the first 6 races either due to collisions or car problems. Grosjean and Maldonado collided with each other, in Spain and Britain. A highlight of the season however was Grosjeans podium finish in 