(CNN) -- Williams and Toro Rosso both unveiled their cars for the 2012 Formula Season on Tuesday as the first official preseason testing event began at the Jerez circuit in Spain. Williams, a legendary name in F1 with nine constructors' titles but none since 1997, hope the FW34 will help the UK-based team improve on a disappointing 2011 campaign which produced just five points in 19 races. Williams recruited Brazilian Bruno Senna as a replacement for his veteran compatriot Rubens Barrichello, who is without an F1 seat for the first time since 1993. Senna is following in the footsteps of his legendary uncle Ayrton, a three-time world champion who died following a crash at Imola in 1994 in his third race for Williams.
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Williams and Toro Rosso unveil new cars at Jerez on Tuesday
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F1 teams are at the Spanish circuit for a four-day preseason test event
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Brazil's Bruno Senna will race for Williams, following in the footsteps of his uncle Ayrton
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Lotus' 2007 world champion Kimi Raikkonen led the way on the first day of testing
"It feels great to be back with the team and to start putting some mileage on the @placeholder," said the 26-year-old.