I grew up in a place where your car could easily disappear if you left it unlocked so I have always locked my car doors. I then spent 25 years in a place with extremely low crime rate. Almost all my friends never locked their cars at home or a store, but I always did. Good habit for sure! Maybe I should have said when I left my machine in my car at work that I was in a military contractor parking lot with restricted access and guards monitoring video cameras. I still locked my car!

Thank you all for your input. Fortunately I don't live in an area where theft is a big issue. Plus my parents drive way gets packed and makes for no easy get aways if there was a break in.

the good news is that I put the machine in my niece's car. It sat in 40 degree temperature for several hours and it was not affected. Works just fine :) Now I know

A short time if fine. The main thing to do is not turn it on until it has been inside for a while to warm up. Just like you would a laptop, in cold or hot, make it room temp before turning it on.

My cousin used to laugh at me. When I drove my convertible with the top down, I would lock the doors every time I parked it. It is a very good habit.

Had a friend leave her 15000 in car (of course it was 100+ here in the summer); melted the mother board and had to be replaced. I would never, never, never leave my machine in the car; it is like my child, take care of it. And, if the heat (doesn't get that cold here, so can't say about the cold, still wouldn't leave it)doesn't get it I would not want car to get broken into and get stolen.

Machine makers aren't going to risk machines being ruined by temps in shipping and storage.
Machines are shipped encased in thick styrofoam molded to fit the machine. That keeps the machine protected from temperature changes. Not many get or keep the original packaging which would be the safest way to keep a machine safe from temp changes.