2005 saw Alcaraz claim the Spanish Championship ICA Junior title, beating countryman Roberto Merhi by four points, and finish third in the Andrea Margutti Trophy ICA Junior class, behind Merhi and Charles Pic.

His final year of karting in 2006 saw Alcaraz claim fifth place in the World Cup ICA class.

[3] In November 2007, Alcaraz sampled a Formula Renault 3.5 Series car for the first time, driving for Pons Racing at the opening winter test at Paul Ricard.

[4] Despite an encouraging start to the season, when he finished in the points in only his second race, he left the team after the fourth round of the year at Silverstone and was subsequently replaced by Brazilian Claudio Cantelli.

[5] Alcaraz did, however, return to the series at the following round of the season in Hungary, taking the seat of Máximo Cortés at Pons Racing, who had run into sponsorship problems.