The problem with using a fogger in a car is that it is not designed with that purpose in mind. If you found a brand that was specifically designed for that it would be much safer. I wouldn't use this in my car or tell you to do so.
Some health concerns may be excessive exposure to pesticides through skin contact. Also, since it is winter, the chemicals may be continually cycled through the cabin of the car which could be hazardous to the respiratory tract.