How long is it good for?!
Answers:
Assuming your steak was beef, that time is okay, even though it likely wasn't -9 in your vehicle. The food danger zone lies between 40 and 140 degrees Fahrenheit and it doesn't really present a concern until 2 hours have expired (strangely enough, when I initially took my training 25 years ago, this time was pegged at 4 hours).
Yes that is true, as long as its kept cold (no matter where it is) you can definitely keep it out longer but i would advise you put it in your freezer as soon as you have the chance.
the temps outside are clearly colder than anyones refrigerator and even though your car was probably heated, you most likely did not sit the steak under the heat vent.
IT is fine.