Overall the team was very pleased with the outcome of the day.
Maldonado was fastest in Barcelona Wednesday, ahead of Rosberg, who spent part of the day testing the controversial 'megaphone' exhaust.
Mercedes tested a 'megaphone' like component Wednesday, in hopes of amplifying the engine sound.
McLaren's cars might look a little bit different at this weekend's Spanish Grand Prix.
Bernie Ecclestone said that we have to wait and will see what happens.