McLaren debuted a radical front nose as the final week of pre-season testing kicked off at Barcelona on Tuesday.
Jenson Button took to the Circuit de Catalunya with a bulbous lump on the nose of his MP4-26, connecting rods to the extremities of the front wing.
It is believed the setup is a tool to accurately measure front wing 'flex', after McLaren was out-foxed in this area by - notably - Red Bull and Ferrari last year.
Meanwhile, a McLaren spokesman confirmed reports the British team will not be running in Spain on Thursday.
McLaren's schedule will therefore effectively be two back-to-back tests on Tuesday-Wednesday and Friday-Saturday.
It also emerged in Barcelona on Tuesday that Nick Heidfeld, replaced on the opening day by his teammate Vitaly Petrov, is sitting out the action with a cold.