How do you beat Belloq in Lego Indiana Jones 2?

Answer 1

You need two players for this. There are three jungle cutters: One you currently ride, another a soldier is riding and the last one Spalko is riding. While you are on a jungle cutter, have your buddy defeat the last 6 cars until Spalko appears. While riding the Jungle Cutter, hit her in the back and you'll complete Rainforest Rumble.

Answer 2

Go to the left and use Marion to jump up the cliffs to push a crate off. Build a light sensor and push along the tracks to break the right wall. Go right and use Indy to whip three platforms and jump up and grab a piece of machinery and place on the machine. Use Marion to get the other part and put it on. Build the light sensor the crumbles apart to break the left wall. The buttons in front of the generator will then pop up, leaving You and Marion to push one button. This will reflect lightning back at Belloq, making him go out with a bang after the lightning apparition shrinks back into the Ark then you've completed Belloq Battle.