Don't think this has been mentioned yet:
from http://www.firstgroup.com/scotrail/content/home/VIEWtravel.php?id=00000000023Caledonian Sleeper Lounge cars to be non-smoking
From Sunday 9 October 2005 smoking will no longer be allowed in the Lounge Cars of Caledonian Sleeper services. A no-smoking policy will operate throughout the trains.
With this change, all First ScotRail services (daytime and overnight) will now be non-smoking.