I've posted this in another thread but maybe some haven't heard. I live way out in the boondocks and have plenty of mice. This summer I trapped many and still didn't notice any reduction. The irritating thing is the nests they will build in the engine compartment of your vehicle. I've tried most everything once. Moth balls, dryer sheets, peppermint, even urine on shop towels. Nothing works for long.
Well, I finally realized what was so attracting about vehicle compartments. It's an enclosed space, up off the ground and with a nest it's probably fairly warm.
So four months ago I began opening the hood on all my vehicles and leaving them open. Close the hood when you use the vehicle - open it when you get home.
Guess what - - no mice, no mice nests in ANY of my vehicles for the last four months. I do this as a routine practice now and it works for me.
Give it a try - you have nothing to loose.