Bob Kakis wrote:
It is a notebook. It is meant to be used anywhere.
Anywhere? According to Apple it is not even meant to be used on your lap.
The laws of physics don't care where or when or how we would like to treat our equipment nor what is convenient.
If your hard drive platters are colder than the dew point temperature of the environment they are in then moisture WILL condense on them. The read/write heads fly much less than one thousandth of an inch above the platters. How much condensation can they afford to have on them?
If your bag is well insulated and the MBP is in Sleep mode, all the better, because it generates heat in that mode. If it is shut down the heat it generates is immeasurable.
You might get away with the cold car storage for a month or two or three then all of a sudden, one night it gets just a bit colder or for a bit longer, or the house is a bit more humid and botta-bing! There you go. Time to replace the drive and restore it with the cloned copy of it that you keep warm and dry.
As stated earlier, if it is a airtight bag in the car then brought inside and allowed to fully warm before removing it from that bag, then no moisture is going to condense on it. If there is no bag then you would want to let it warm much longer because you need to be certain that the HD platters are dry. There is no way you can know when they are dry just by asking someone on a forum. It all depends on temps, time, humidity and bags.
Whether or not the moisture indicators will turn color is just a guess. I have not seen any printed data showing how they operate and under what conditions it takes to activate them. And besides, if they tuirn pink that does not ruin your data it only voids your warrantee, and that is only a maybe.