We’ve all heard the admonition about not storing trains in anyplace other than temperature controlled areas. I do this with motive power and cars such as my talking diners, but not for regular cars .
I relieved the clear car cushion packing and stored my Lionel Sunshine Special cars with the diaphragms in. The summer heat in my shop outbuilding baked the diaphragms hard and they had some distortion. Not good!
Other Lionels and MTH were ok...