Motoyama has competed at the 24 Hours of Le Mans four times, making his debut in 1998 with NISMO and Tom Walkinshaw Racing in one of four factory Nissan R390 GT1s. Motoyama, Masami Kageyama, and Takuya Kurosawa drove the #33 JOMO R390 GT1 to a tenth-place overall finish, ninth in the GT1 category. Motoyama returned the following year in 1999 with NISMO, driving the new Nissan R391 Le Mans prototype. Motoyama and co-drivers Érik Comas and Michael Krumm ran as high as fourth place overall in the #22 R391, before retiring after 110 laps with an electrical issue.