since we had a tour company, the luggage stayed at the bus/ car. ( we have used both depending on the size of our group)

The driver stayed at the bus with the luggage

In general all locals are aware of how muy value tourism brings to the area and are respectful

We never had luggage while we were touring. However, based on my experience with the tours it shouldn’t be a problem as the driver always stayed with the car.

Our luggage was taken care of by the tour operator. After visiting sacred valley, all our bags were waiting for us at the hotel.

Yes. We left the luggage in the car as the driver stayed with the car while the guide took us around

We were in a large group with a couple of buses, so it wasn't an issue for us. I think your luggage would be safer in your car in the Sacred Valley than in most sanctuary cities in the US.

We used a private guide and driver and left our luggage in the car. The driver stayed with the car and we never had concerns about the luggage being stolen.