Brings to mind...my bass player, and the '65 Fender Precision he had stolen from a locked vehicle, in a locked garage. If someone wants your stuff bad enough, and they've staked you out...they'll find a way of parting you with your goodies. Just a heads up.
As for the temperature aspect. I try to avoid that scenerio at all times, only because as Smurf stated, the temperature fluctuations and condensation can really do a number on your equipment, and you don't want to find that out as you're setting up for a gig...do you??

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...L