With the financial support of his father, Marcelo raced in junior formulas in the United Kingdom before moving to the New Zealand series.
In 1990, Marcelo returned to the United States and competed in the Toyota Atlantic Championship with Duane Anderson's team.
Marcelo competed in three CART PPG Cup events, finishing 14th in Surfers Paradise (Australia), 19th in Phoenix and 19th in Long Beach.
In May, Marcelo was entered in the Indianapolis 500 driving a Lola T91/00-Cosworth DFS and participated in rookie orientation and practice for the event.
Frankie Muniz won the 2008 IMSA Cooper Tires Atlantic Championship Jovy Marcelo Sportsmanship Award.