I cut the body of my car like this. I have thin sheets of balsa and birch. To make the weight pocket, I planned on using some 5 min Epoxy to glue a square of the birch or balsa (does it matter which) to the top of the holes at the back of the car to create weight pockets. Then, I’ll put the double sided tape on the square of balsa and stick the weights on that. Then, after we get the weights right, I was going to put some foil tape across the bottom of the car to hold everything in place. Is that how I’m supposed to do it?