I have included the baked animation file for anyone curious about my workflow for the actual transformation. It's mainly hiding and unhiding pieces (in the camera view) of geometry when I animate the car parts to the corresponding robot parts. Adding motion blur definitely helps with the transformation. I also save two poses into Studio Library - one for the T Pose and the other for when he's crouched to fit into the dimensions of the car. You can then easily blend between the pooses without having to adjust each controller individually. You'll have to hide a few peices as well in this crouched pose so they dont stick out. You can save out the pose from the animation file if you'd like.

Email me at nithinderana@gmail.com with any questions regarding the rig.