Minecarts make walking sounds when moving after they've been pushed off and back on rails.
- Create a circular rail loop using both normal and some powered rails (see attached video)
- Put a Minecart on the rails and push it so that it starts moving along the placed rails
- Destroy a rail block and push the Minecart off the rail as soon as it arrives at the broken part
- Push it back on the rails and place the rail again
- Fly up / don't move and listen carefully–the Minecart will make walking sounds while moving