not entirely true. Collisions between particles are very different to collisions between cars. Particles are very nearly point-masses, and very nearly incompressible, so you don't have the issue that you have with the car, which is that some components will be compressed into the wreck and not be ejected. Along with that, of course, is the fact that you definitely won't find a wrench small enough to take apart a proton.
I see your point, it is a fairly brutal and primitive method to divine the contents of these particles, but without it we wouldn't have discovered the muon, the gluon and the six types of quark. There may be more we can discover in the same manner