I've stumbled over Rebrickable recently where you can enter a LEGO set number and get alternative models (MOCs) and build instructions for them (among other usa

I've stumbled over Rebrickable recently where you can enter a LEGO set number and get alternative models (MOCs) and build instructions for them (among other usages). For my children there is lots of fun in taking apart the car again and building a plane from the same parts. This also has the benefit of keeping the sets together (for now), so the original instructions can still be used without having to hunt for two 1x1 tile rounded in dark blueish gray in one of the two big boxes of parts. It varies by set/model. Some of them are built and then played with, some are built, razed, built differently, demolished again. Some are built and then put on display. The pieces, even the specialized ones, are rarely the problem in building something completely different from what I can observe. They are, however, a problem when you have to find them again if you want to build the original model.