The fridge and freezer were measuring a little warmer than previous campers we've had and our home fridge. After reading this forum, and others, I tried a fan to stablize the temps. Prior to the fan the fridge was 40 deg, frezzer was 20 deg. Home freezer is about 0 deg and fridge is about 34 deg. I bought a couple fridge thermostats off amazon that hang on the fridge/freezer gates.
After installing the fan, within a few hours the temps in the fridge came down. I don't think everyone see's this as a problem, but if you find yourself wondering why the soda pop is not as cold as you like, this could be an easy troubleshooting tip.
I got mine of ebay for $20. Norcold refrigerator deluxe fan with grill. Install was very easy with no drilling.
I agree with JohnD, vent covers are a must.... Other than keeping rain out with vents open, it's a little insurance on your vents as well. We have a vent in the loft bed that can mistakely be left open and undetected before traveling. I'd rather have the vent cover than loose a vent going down the highway. Those vents can also get blown out with a little hail (ya ever get hail!). When using the furnace in the winter months (or just camping in the winter months) condensation can build up on the inside of the camper (mostly windows). Keeping a vent cracked open can help reduce that condensation. (side note: keep your fridge door open when not in use. mold can develop quickly in the enclosed fridge after you turn it off if not ventilated)
I put a black vent cover in the loft bed. Black vents help knock down the sunlight in areas you want kept darker. I used while vents covers over the bath and kitchen vent to help keep sunlight coming in those areas.
If your in a high humidity area, some folks will keep their vents open during storage times because of mildew and mold problems in damp climates. I've read where folks (mostly in pacific northwest) will open the camper in the spring and find moldy/mildew walls because of the dampness without ventilation inside the camper.