McLaren car has weaknesses - Jenson Button

McLaren's Jenson Button says there are "quite a few weaknesses" with his car after he finished 2.386 seconds off the pace in second practice at the season-opening Australian Grand Prix.

Button's teammate Sergio Perez says the car is "unpredictable" and "difficult to drive". But world champion Sebastian Vettel described the first day of the season as "very good" after he headed both practice sessions.

Red Bull team-mate Mark Webber was just behind him in the second session while Mercedes's Lewis Hamilton was seventh.