There isn’t a way to revert the behavior unless you go back to using 4.11, however; I’m not sure why you were seeing this behavior to begin with. Every version of the engine I’ve used has the behavior that I explained above. Maybe 4.11 had a bug that I didn’t know about?
Most people that create realistic car wreckage in UE4 use a series over overlapping boxes and on overlap they swap (or sometimes morph) different parts of the car to simulate damage.
You may also be able to accomplish this by using a GetClosestPointOnPhysicsAsset based off the BreakHitResult. But you would have to set up your vehicle from scratch to work with this method. You will see what I mean if you play around with the setup in the Advanced Vehicle template.