Tom : We have used moth balls with some success but we put them under the car rather than in it so we didn't have to live with the odor inside the car. I read somewhere that Bounce dryer sheets will work to. I tried that this past winter & I didn't see any mice & the car has a nice smell but I am not sure how well that works as I only tried the one time. Les Fairbanks [Non-text portions of this message have been removed]