The car is scheduled to go through 20 days of track testing, and considerable design refinement, between now and its competition debut in Bahrain March 12.
Team drivers Juan Pablo Montoya and Kimi Raikkonen will turn their first laps in the new car later over the next few days.
The MP4-21 is the last McLaren from the pen of Adrian Newey before he left McLaren to join the Red Bull team.
Lots of pictures after the jump!
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