How do I animate a trackless ride to work properly in-game?

I will keep this short, sweet, and simple. I am making a trackless ride. Yes, I know how to animate the trackless ride, however, when I export it and do everything as I would with any other animation, it doesn't work.

I have one model that controls the doors and base of the ride because they are welded, and another model as the cart. Do I put the script for the animation in the coaster cart or the model that controls everything for the cart?