Complex sentence: They participated in 30 Grands Prix, initially entering cars bought from Team Lotus, before finally building a car of their own, the Rebaque HR100 was entered for the team's final three races before the team's closure.
Split into simpler sentences: They participated in 30 Grands Prix, initially entering cars bought from Team Lotus, before finally building a car of their own. The Rebaque HR100 was entered for the team's final three races before the team's closure.