We've read about trains that have some open cars on the Bernina Express route from Chur to Tirano and we'd like to try those if possible! Are these cars available in September or is it too cold at that time of year for them to be offered then? Also, are they only available on the official Bernina Express train or on some of the private trains?
Do we need to book the train for that trip now or wait till we get there? Many thanks!
The only thing I am aware of is the Furka Steam train excursions that run through Sept 28.
http://www.sbb.ch/en/leisure-holidays/holidays--short-breaks-in-switzerland/scenic-trains/weitere-panoramareisen-landingpage.angebotdetail.ferien_kurz_trips_schweiz-panoramazuege-furka_dampfbahn.html
Along the Bernina route, there is the Albula experience train from Landquart to Samedan, running on Sundays only through September 7, 2014. It's possible that the open cars are also added on other sunny days through early September, as described on p. 352 of Rick's Switzerland book, but that was not confirmed as recently.
Thanks for your help!