SetAllBodiesBelowPhysicsDisabled functionality appears to leave bodies behind that raycasts can still interact with.

From UDN

We use SetAllBodiesBelowPhysicsDisabled() to disable some bodies of our Vehicle.

However by drawing the disabled bodies' particles position, we found those particles stay where they disabled. When we do line trace at the location where we disable, the hit result returned those particles. That means we do a line trace, but get a actor far from the trace location.

This is not specifically a vehicle problem SetAllBodiesBelowPhysicsDisabled is a function on the skeletal mesh and wheel traces are simply standard raycasts.  

UDN steps:

1.Spawn an vehicle A and disable some physics bodies.

2. drive the vehicle away

3. Another vehicle B passed by the A's disabled bodies in a second, B's suspension system (or raycasts in general) will trace A's disabled bodies.

Expect: The disabled bodies are gone and nothing should interact with them at the position they were disabled.