I have heard that there are auto trains that run between Switzerland and Italy. Since we have some distance to cover by car, we wanted to know what routes these trains take and the schedule and prices. The only information I have found about them is very general, but I cannot find specific schedules or routes, only for regular passenger trains. Do you have the information I am seeking?
https://www.sbb.ch/en/station-services/auto-velo/car-trains.html
We returned from Tirano to Klosters through the Vereina Tunnel (19 km) on a passenger train. The auto trains use the same route to shortcut the travel between two valleys. Vereina price and timetable information: https://www.rhb.ch/en/car-transporter#timetable
Please note that you cannot specify a particular train. We do not
accept reservations!
The auto trains in Switzerland cover short distances through the Alps where there is a rail service (usually in a tunnel), but either no road, or the road is closed by snow in the winter. These are the ones in Edgar's links. They have a continuous shuttle service, the journeys take less than 30 minutes and you stay in your car.
I think what you are looking for is usually called Motorail, travelling long distances, usually overnight, where you travel in a sleeping car on the same train but separate from your car. There are none of these from Switzerland to Italy. Generally Motorail services have been dying out in recent years, same as have all sleeper trains, as they cannot compete with High Speed day trains and cut-price airlines.
The ones that do remain are described on this webpage: https://www.seat61.com/Motorail.htm