Masuoka's most notable achievement was his back-to-back successes in the
Dakar Rally in 2002 and 2003, only the fourth driver in the event's history to win in consecutive years. He was also victorious in the 2003 Baja Italy and the 2004
UAE Desert Challenge. Throughout his career he has been employed as a works driver by
Mitsubishi, typically driving a
Pajero. The
2009 Dakar Rally was his 21st and final participation in the rally, after which he retired along with Mitsubishi's withdrawal from the event. During his Dakar career, he won 25 stages, putting him fifth in the all-time list for the car category. He is now Senior Expert of Mitsubishi's Public Relations Department. ==Personal life==