LONDON, England - McLaren launched its 2013 F1 car on Jan 31 at its factory in Woking, southern Engand, but a notable absentee was technical director Paddy Lowe.It's been confirmed that Lowe, initially in talks with rival team Williams, has also discussed a move to Mercedes.McLaren team boss Martin Whitmarsh said during the launch of the evolutionary MP4-28 cars that Briton Lowe, 50, would stay with the team for 2013 but after that "the future is less certain".PULL-ROD LAYOUTWhy did Lowe avoid the launch? Whitmarsh said the technical director made the decision himself to save the team the "embarrassment" of facing up to the recent controversy on the eve of McLaren's 50th anniversary.Whitmarsh said Lowe didn't want to be a distraction. "At his own election he felt it was inappropriate to be here. He'll be part of the team for the rest of this year."McLaren has followed Ferrari's lead by switching to a novel 'pull-rod' layout for the MP4-28's front suspension and the drivers for 2013 will be Jenson Button and new arrival Sergio Perez.McLaren said in a statement: "The MP4-28 isn't merely a refinement of last year's seven-race winning car... it's a deep and sweeping redesign of an already successful chassis in several key areas."