At the beginning of 2007, Kobayashi, along with Kohei Hirate, was named as one of the Toyota Formula One team's test drivers. He stayed in the Euro Series for the upcoming season and had an impressive start, taking two podiums in the first four rounds. He achieved his first race victory in Formula 3 at Magny-Cours, in the tenth round, a support race for the Formula One French Grand Prix. Kobayashi finished fourth in the Drivers' Championship.