Like many racing drivers, Molina started his early motorsport career in karting, winning successive Spanish Cadet Championships in 1999 and 2000, as well as the Catalonian Junior Championship in 2001 and Spanish Junior Championship in 2003.
In 2004, Molina began his circuit racing career in the Spanish Formula Junior 1600 series, where he finished the season in 6th place. The following year he stepped up to the Eurocup Formula Renault 2.0 championship with Pons Racing, scoring three points to finish the season 28th overall. In 2006 he switched to the Spanish Formula Three Championship with the Racing Engineering team, taking one race win and a further five podium finishes to end the season 6th overall. He also drove for GD Racing in the final six races of the World Series by Renault season, scoring a point in the final race of the season at Barcelona.
For 2007, Molina moved up to the World Series full time with Pons Racing, scoring two race wins (at Estoril and Barcelona) and two further podium places on his way to 7th in the final standings. In 2008 he once again competed in the championship, teaming up with fellow Spanish driver Álvaro Barba at Prema Powerteam. He claimed four podiums during the season, including two race wins at Nürburgring and Estoril, to finish 4th in the championship. After testing for Prema, Epsilon Euskadi and KTR during the off-season, Molina was signed by Ultimate Signature for the 2009 season.
Molina is also a member of the Circuit de Catalunya Young Drivers Programme.