I have never had problems with plastic water bottles freezing and bursting. I have not had problems with tinned food bursting the cans either, though some of them did bulge a bit at the ends.

I found most chocolate bars melted and got a white bloom on them from the summer heat, but they were still perfectly edible.

The cold part is Canada. I am not sure if it gets as hot inside my car in the summer as yours might get. I do know it gets hot enough to melt plastic things if you leave them on the dash.