Arizona Kid is right about the concern being stated for gas build up going down the road. I have never figured that one out, personally. How can gas from a failed ignition build up in a vented, outside place with a sixty mph wind blowing by? I guess the comment is right on target: it depends on how the model if configured.
The best $12 you can spend on a refrig is to buy a little inside/outside wireless thermometer and keep the outside transmitter in the refrig and the inside unit velcrowed to your dash. You can monitor the refrig's temp going 24/7. Especially handy for me because my DW is a worrywart and is concerned with a failed refrig spoiling all our vittles. :)