^^ That's by far the most serious, in-depth, thought-provoking, on-topic post from Andre!
Don't know if seran wrap would do any harm but I think as long as you can have your intake and exhaust tips covered you should be fine. I use foil since it's easier to shape. You may get away with just plastic bags and rubber bands. The intake I talked about is the air intake itself not the vents/openings under the bumper. But to cover the whole front is a good idea too to keep the mice from doing any housekeeping inside there.
I can't tell you if size matters in this situation but a heated box would take care of a lot of moisture-related problems so you don't have to squeeze yourself in that tight space doing too much work.
