Yesterday I was looking under the hood of our Sonata and decided that I would pop the plastic cover that covers the plugs and wires. I pop the cheap plastic cover off and there was evidence of a mouse or rodent household, several cotton balls and strands of cloth, some remnants of shoelaces and several discarded walnut type shells as well as probably a half a cup of what appeared to be dry cat food along with a good deal of bird seed and sunflower seed. I got my wet/dry vac and got it all out. No signs of chewed on wires which was good. We drive that car at least 2-3 times per week. I am guessing that as soon as vehicles starts the rodent leaves,It would be far too hot to stay there for long while engine is running. I suspect that the bird and cat food is from local neighbors who feed feral cats and birds. I quite often see feral cats carrying mice that they killed, but apparently the cats cannot keep up with the rodent population, either that or the cats are slacking. Anyone else here on BITOG ever find mice nests on vehicle that you drive frequently? One co worker told me that he has soaked a few wood chips in tabasco or mint oil, but that was for a vehicle in storage. Any other techniques to deter these rodents.