Building cars is a more "expensive" hobby than it appears on the surface. Do you recycle your tungsten, wheels, and axles? I'm torn between keeping cars intact to compare past/future builds and salvaging parts.
I reuse axles and wheels....I simply place stock axles and wheels on the kids cars so they can have them on their display shelf. Take pictures of your build and keep a log of all runs the car makes that way you can compare that car to future builds.
I glue cubes together into larger blocks with CA and then a couple small drops of CA on the larger block hold it firmly in place. When done with the car a little twist of a screwdriver will usually break the large block free for reuse.
I recycle weight. Certainly can’t afford to be buying more over and over again. I use the 2 sided thin clear tape in window plastic sealing kits for winterizing against drafts. It holds perfectly and the cubes pop right off with the right pressure and twist. No risk of damage to the body at all. And I have never had a weight come loose.