Not sure this works, but it makes me feel better!!
Many people in the SW report damage to their car's wiring from hungry little rodents. Apparently, these little guys hate light - so most folks leave their hoods up and/or put a flashlight on the engine at night. I don't worry too much about the trailer as it's sealed underneath - not much for rodents to get into.
I have some solar light strings.
Lately, I've been laying out a line of solar lights and then parking the car over it. That way, after dark I have lights under the SUV. Sometimes, I put a couple of cheap solar light sticks on the engine block and raise the hood a bit. The lights seem to last a whole night.
I like the solar light strings that can be unplugged from the solar panel - that way I can put the solar panel in the sun if the car happens to be in the shade. Then, after dark, I just plug it back in to the light string.