LONDON, England - Romain Grosjean has put his troubled start to the 2012 season firmly behind him, according to a Lotus team engineer.Brazilian Ricardo Penteado, employed by engine supplier Renault, actually works on Kimi Raikkonen's car.After the Frenchman's troubled start to 2012, culminating in a new chassis for the 27-year-old in Bahrain, Grosjean finished on the podium last time out in Bahrain.ALL IN THE PASTPenteado thinks such a performance shows Grosjean has moved on from 2012, when Mark Webber branded him a 'first-lap nutcase' following a string of crashes."I think he can forget about 2012 now," he told Brazil's Totalrace. "His overtaking was all perfect; he didn't put anyone out. It was clean and really showed who Grosjean is - especially his speed."He showed in 2012 that he is a very fast driver and I would say he can use the systems of the car even better than Kimi. His challenge is to find the right set-up... and having a little more confidence in himself," said Penteado.