McLaren are usually expected to be Ferrari's closest challengers but made a complete pig's ear of the first half of the 2004 season.
Engine: Mercedes V10
Team principal: Ron Dennis
Years in F1: 38
2004 position: 5th
Drivers' titles: 12
Constructors' titles: 9
It soon became obvious that a decision to start the year with an updated version of a car that was first slated to race in 2003 was a major error.
But the team rescued their season by producing a new car mid-season.
This immediately took the fight to Ferrari, and helped Kimi Raikkonen to a brilliant win in Belgium.
Technical director Adrian Newey never agreed with the plan not to produce an all-new car for the start of 2004.
And his wisdom became clear when the MP4-19 proved both slow and catastrophically unreliable at the start of the season.
But McLaren poured millions into major surgery on the car and Mercedes worked hard at ironing out the weaknesses in the engine.
And their progress merely underlined what formidable competitors McLaren are when they get things right.
The MP4-19B had revised aerodynamics and rear suspension but still bore some of the compromises inherent in the MP4-19.
An all-new car will be produced for 2005. Those who wish for a competitive season and some opposition for Ferrari must hope McLaren and Mercedes get this one right first time.