Personally, I would be more concerned that the temperature in ur trunk might get too hot for ur plants, especially if u r parked outside in the sun on a hot day. Do u have a trustworthy friend who would let u leave ur babies at their place until u get out of work and the inspectors are gone? I don't believe the change in the light cycle will do much damage. I grow indoors in a closet and last summer we had a terrible thunderstorm that knocked the power out about 6 hrs b4 the time they usually get darkness and it didn't come back on for about 6 hrs after the light should have come back on. My babes came thru with no problems. I ended up harvesting about an ounce of dried product from each plant and they were only about 18" tall at harvest time.

I hope this helps. good luck with ur babies.