@endo1 recent example: stunt team came and set up a steel mechanical beam with wire rigging for a murder victim (stunperson) to 'hang' from. Carpentry department skinned it to look like a barn beam. Sets then dressed it in real (but non-practical) ropes and knot work for depth and realism.
Following that example,
@Wor-Gar would be correct in accusing Sets of bubble-wrapping the straps, but I don't know how Lucasfilm's crew worked back in the late '70s and early '80s. Sets doesn't generally touch picture vehicles when I work, but the snowspeeder is a rig on a set, not a vehicle.