I have on occasion taken my fiddle to parties (of nonmusician friends) and will only play if people ask. Lately I just dont bother (unless Im going camping or something) I would never leave it in the car because it could get stolen and the temperature thing (In one party at wintertime I did that and kept on going out of tune due to the temperature changes when I brought it in)
One of my friends parked his car in bad part of town and left his set of uilleann pipes in there. By the time he got back it was too late... / . Someone put in another set of uilleann pipes. Petr.