Nico Rosberg , says the sport 's dominant team `` definitely has n't peaked yet despite Mercedes having won all four of the season 's opening races . Nico ##l warns that Mercedes have not peaked yet . Mercedes have won all four Grands Prix so far this season . Rosberg leads drivers ' championship race . Spanish Grand Prix takes place in Barcelona this weekend .
Nico ##l warns that Mercedes have not peaked yet . Mercedes have won all four Grands Prix so far this season . Rosberg leads drivers ' championship race . Spanish Grand Prix takes place in Barcelona this weekend .